0001564590-21-015506 | 10-K | XBRL Viewer

Stockholders' Equity (Redeemable Convertible Preferred Stock) - Additional Information (Detail)									1 Months Ended			3 Months Ended	12 Months Ended
	May 09, 2019 $ / shares shares	Nov. 12, 2017 USD ($) $ / shares shares	Oct. 11, 2017 USD ($) Investor $ / shares shares	Jul. 14, 2017 USD ($) shares $ / shares	Oct. 30, 2014 USD ($) $ / shares shares	May 23, 2014 USD ($) $ / shares shares	Dec. 26, 2013 USD ($) $ / shares shares	Dec. 04, 2012 USD ($) $ / shares shares	Jan. 18, 2019 USD ($) $ / shares shares	Aug. 30, 2018 USD ($) $ / shares shares	Jan. 31, 2014 USD ($) Number $ / shares shares	Mar. 31, 2019	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2019 USD ($) shares	Dec. 31, 2018 USD ($)	Dec. 31, 2017 $ / shares	Dec. 31, 2014 USD ($)
Temporary Equity [Line Items]
Redeemable convertible preferred stock to common stock and additional paid-in capital \| shares	10,381,234
Dividend rate, percentage	6.00%
Share Price \| $ / shares							$ 1.00
Convertible preferred stock, settlement terms													In addition, TPG had the right to purchase, on the same terms and conditions as the Series B Initial Closing, including the $1.15 per share purchase price, the lesser of 4,347,826 additional shares of Series B Preferred Stock and the number of shares equal to 25% of the total number of shares it previously purchased for cash under the Series B Purchase
Preferred stock additional shares authorized for issuance \| shares													5,000,000	5,000,000
Preferred stock, share, outstanding \| shares													0	0
Risk free rate of preferred stock																1.95%
Volatility rate of preferred stock																78.00%
Weighted estimate of time to liquidity event of preferred stock																2 years 8 months 15 days
Payments of financing costs													$ 84,000
Conversion ratio of preferred stock to common stock												1			1
Common stock, voting rights													holders of common stock on any matter presented to the stockholders of the Company for their action or consideration at any meeting of stockholders of the Company (or by written consent of stockholders in lieu of a meeting), and each holder of outstanding shares of redeemable convertible preferred stock was entitled to cast the number of votes equal to the number of whole shares of common stock into which the shares of redeemable convertible preferred stock held by such holder were convertible as of the record date for determining stockholders entitled to vote on the matter
Measeurement Input, Discount for Lack of Marketability [Member]
Temporary Equity [Line Items]
Fair value estimates of common stock discount rate													0.47
Measurement Input, Probability Factor [Member] \| Non-IPO Based Scenario [Member]
Temporary Equity [Line Items]
Probability factor													60.00%
Measurement Input, Probability Factor [Member] \| IPO Based Scenario [Member]
Temporary Equity [Line Items]
Probability factor													40.00%
Discount Rate [Member] \| Non-IPO Based Scenario [Member]
Temporary Equity [Line Items]
Fair value marketability discount rate													20.00%
Measurement Input, Cost of Equity Estimate [Member] \| IPO Based Scenario [Member]
Temporary Equity [Line Items]
Expected pre-money valuation													15.00%
Measurement Input, Expected Term [Member] \| IPO Based Scenario [Member]
Temporary Equity [Line Items]
Estimated time to IPO date													4 months 17 days
Initial Public Offering [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares	7,000,000
Share Price \| $ / shares	$ 10.00
Stock issued during period, value, new issues														$ 48,174,000
Accrued dividends converted into common share													$ 18,400,000
Common Stock [Member] \| Initial Public Offering [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares														5,500,000
Stock issued during period, value, new issues														$ 5,000
Redeemable Convertible Preferred Stock [Member]
Temporary Equity [Line Items]
Dividend rate, percentage	6.00%
Redeemable Convertible Preferred Stock [Member] \| Initial Public Offering [Member]
Temporary Equity [Line Items]
Preferred stock, share, outstanding \| shares													0	0
Conversion ratio of preferred stock to common stock													0.105	0.105
Redeemable Convertible Preferred Stock [Member] \| Series B Purchase Agreement [Member]
Temporary Equity [Line Items]
Stock issued during period shares additional issues \| shares						4,347,826
Number of shares equal to number of shares previously purchased for cash percentage						25.00%
Shares issued, price per share \| $ / shares						$ 1.15
Series A Redeemable convertible Preferred Stock Member [Member]
Temporary Equity [Line Items]
Redeemable convertible preferred stock to common stock and additional paid-in capital \| shares								1,207,923
Stock issued during period, shares, new issues \| shares							6,500,000	6,000,000
Share Price \| $ / shares							$ 1.00	$ 1.00					$ 1.00
Adjustments to additional paid in capital, stock issued, issuance costs							$ 39,000	$ 128,000
Proceeds from issuance of redeemable convertible preferred stock							$ 6,500,000	5,900,000
Convertible notes payable								$ 564,000
Debt instrument, convertible, conversion price \| $ / shares								$ 0.467
Stock issued during period shares additional issues \| shares								4,000,000
Number of shares equal to number of shares previously purchased for cash percentage								25.00%
Convertible preferred stock, settlement terms													In addition, TPG had the right to purchase, under the same terms and conditions as the Series A Initial Closing, including the $1.00 per share purchase price, the lesser of 2,500,000 additional shares of Series A Preferred Stock (the “Additional Series A Preferred Shares”) and the number of shares of Series A Preferred Stock equal to 25% of the total number of shares of Series A Preferred Stock it previously purchased for cash under the Series A Purchase Agreement.
Preferred stock additional shares authorized for issuance \| shares							2,000,000
Shares issued, price per share \| $ / shares											$ 1.08
Preferred stock redemption period											3 years
Preferred stock, value, outstanding															$ 21,000,000
Series A Redeemable convertible Preferred Stock Member [Member] \| Series A Extension Purchase Agreement [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares											1,680,000
Share Price \| $ / shares											$ 1.00
Adjustments to additional paid in capital, stock issued, issuance costs											$ 7,000
Proceeds from issuance of redeemable convertible preferred stock											$ 1,700,000
Number of preferred stock shareholders \| Number											8
Proceeds from issuance of redeemable convertible preferred stock before issuance cost											$ 1,800,000
Preferred stock, discount on shares											$ 134,000
Amortization of stock issuance costs													$ 0	$ 7,000
Series A Redeemable convertible Preferred Stock Member [Member] \| Series A Extension Purchase Agreement [Member] \| Common Stock [Member]
Temporary Equity [Line Items]
Unaccreted discount														5,000
Series A Redeemable convertible Preferred Stock Member [Member] \| Maximum [Member]
Temporary Equity [Line Items]
Stock issued during period shares additional issues \| shares								2,500,000
Series B Redeemable convertible Preferred Stock Member [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares					869,565
Share Price \| $ / shares					$ 1.15								$ 1.15
Adjustments to additional paid in capital, stock issued, issuance costs					$ 19,000
Proceeds from issuance of redeemable convertible preferred stock					$ 10,500,000
Shares issued, price per share \| $ / shares					$ 1.10
Proceeds from issuance of redeemable convertible preferred stock before issuance cost					$ 11,000,000
Preferred stock redemption premium					$ 478,000
Preferred stock, accretion of redemption discount													$ 0	31,000
Preferred stock, value, outstanding															33,700,000
Series B Redeemable convertible Preferred Stock Member [Member] \| Common Stock [Member]
Temporary Equity [Line Items]
Unaccreted premium														$ 22,000
Series B Redeemable convertible Preferred Stock Member [Member] \| Series B Purchase Agreement [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares						13,043,478
Adjustments to additional paid in capital, stock issued, issuance costs						$ 56,000
Proceeds from issuance of redeemable convertible preferred stock						$ 15,000,000
Shares issued, price per share \| $ / shares						$ 1.15
Series B Redeemable convertible Preferred Stock Member [Member] \| Series B Second Closing [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares					8,695,652
Share Price \| $ / shares					$ 1.15
Series C Redeemable convertible Preferred Stock Member [Member]
Temporary Equity [Line Items]
Share Price \| $ / shares													$ 1.46
Preferred stock, value, outstanding															61,000,000
Series C Redeemable convertible Preferred Stock Member [Member] \| Initial Public Offering [Member]
Temporary Equity [Line Items]
Preferred stock, share, outstanding \| shares													0	0
Series C Redeemable convertible Preferred Stock Member [Member] \| Tranche One [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares			101,707	20,547,946
Adjustments to additional paid in capital, stock issued, issuance costs			$ 19,000	$ 291,000
Proceeds from issuance of redeemable convertible preferred stock			$ 129,000	$ 29,700,000
Shares issued, price per share \| $ / shares			$ 1.46	$ 1.46
Stock issued during period, value, new issues				$ 50,500,000
Number of additional investors \| Investor			2
Series C Redeemable convertible Preferred Stock Member [Member] \| Tranche Two [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares		55,621								7,211,165
Adjustments to additional paid in capital, stock issued, issuance costs										$ 32,000
Proceeds from issuance of redeemable convertible preferred stock		$ 81,000								$ 10,500,000
Shares issued, price per share \| $ / shares		$ 1.46								$ 1.46
Series C Redeemable convertible Preferred Stock Member [Member] \| Tranche Third [Member]
Temporary Equity [Line Items]
Stock issued during period, shares, new issues \| shares									6,849,315
Adjustments to additional paid in capital, stock issued, issuance costs									$ 37,000
Proceeds from issuance of redeemable convertible preferred stock									$ 10,000,000
Shares issued, price per share \| $ / shares									$ 1.46
Preferred stock value outstanding at fair value															2,100,000
Series C Preferred Stock [Member]
Temporary Equity [Line Items]
Shares issued, price per share \| $ / shares													$ 1.46
Percentage of preferred shareholders remaining outstanding													66.67%
Fair value of preferred stock share price \| $ / shares																$ 1.44
Payments of financing costs														$ 379,000
Accretion of financing costs													$ 0	223,000
Series C Preferred Stock [Member] \| Measeurement Input, Discount for Lack of Marketability [Member]
Temporary Equity [Line Items]
Fair value estimates of common stock discount rate													1.44
Series C Preferred Stock [Member] \| Tranche One [Member] \| Convertible Debt [Member]
Temporary Equity [Line Items]
Debt instrument, convertible, conversion price \| $ / shares				$ 1.095
Debt instrument, principal amount				$ 10,600,000
Accrued interest on debt				$ 564,000
Debt instrument, convertible, number of equity instruments \| shares				10,181,233
Series C Preferred Stock [Member] \| Tranche Two [Member] \| Restatement Adjustment [Member]
Temporary Equity [Line Items]
Preferred stock value outstanding at fair value															1,000,000
Series C Preferred Stock [Member] \| Tranche Third [Member]
Temporary Equity [Line Items]
Preferred stock, value, outstanding									$ 1,100,000
Series C Preferred Stock [Member] \| Tranche Third [Member] \| Restatement Adjustment [Member]
Temporary Equity [Line Items]
Preferred stock value outstanding at fair value															$ 1,100,000
Series C Preferred Stock [Member] \| Common Stock [Member]
Temporary Equity [Line Items]
Unaccreted financing costs														164,000
Series A Preferred Stock [Member]
Temporary Equity [Line Items]
Proceeds from issuance of redeemable convertible preferred stock														2,800,000
Shares issued, price per share \| $ / shares													$ 1.00
Percentage of preferred shareholders remaining outstanding													60.00%
Payments of financing costs														166,000
Accretion of financing costs													$ 0	7,000
Fair value adjustment on preferred stock value														520,000
Accretion of investor rights													$ 0	84,000
Percentage conversion of preferred stock outstanding													60.00%
Series A Preferred Stock [Member] \| Measeurement Input, Discount for Lack of Marketability [Member]
Temporary Equity [Line Items]
Fair value estimates of common stock discount rate													0.82
Series A Preferred Stock [Member] \| Common Stock [Member]
Temporary Equity [Line Items]
Unaccreted financing costs														5,000
Unaccreted investor rights														61,000
Series B Preferred Stock [Member]
Temporary Equity [Line Items]
Shares issued, price per share \| $ / shares													$ 1.15
Percentage of preferred shareholders remaining outstanding													60.00%
Payments of financing costs																	$ 76,000
Accretion of financing costs													$ 0	4,000
Accretion of investor rights													$ 0	117,000
Proceeds from series A preferred stock financing														2,000,000
Percentage conversion of preferred stock outstanding													60.00%
Series B Preferred Stock [Member] \| Measeurement Input, Discount for Lack of Marketability [Member]
Temporary Equity [Line Items]
Fair value estimates of common stock discount rate													0.86
Series B Preferred Stock [Member] \| Common Stock [Member]
Temporary Equity [Line Items]
Unaccreted financing costs														3,000
Unaccreted investor rights														$ 85,000

Prepaid Expenses

12 Months Ended

Dec. 31, 2020

Prepaid Expense Current [Abstract]

Prepaid Expenses

3.	Prepaid Expenses

Prepaid expenses consist of the following:

	As of December 31,
	2020		2019
Prepaid R&D payments	$	333	$	1,113
Prepaid corporate insurance		562		491
Other		108		77
	$	1,003	$	1,681

Stockholders' Equity - Shares Reserved For Future Issuances (Detail) - shares	Dec. 31, 2020	Dec. 31, 2019
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	3,646,200	2,778,812
2012 Stock Option And Grant Plan [Member] \| 2012 Stock Incentive Plan [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	921,824	1,043,992
2019 Stock Option And Grant Plan [Member] \| 2019 Stock Incentive Plan [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	2,396,922	1,579,714
2019 Stock Option And Grant Plan [Member] \| 2019 Employee Stock Purchase Plan [Member]
Class Of Stock [Line Items]
Common Stock, Capital Shares Reserved for Future Issuance	327,454	155,106

Nature of the Business - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Apr. 22, 2019	Dec. 31, 2020	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Stockholders equity reverse stock split	one-for-9.5
Net income loss		$ (32,758)	$ (26,050)
Retained earnings accumulated deficit		(146,977)	(114,219)
Cash and cash equivalents, at carrying value		$ 45,001	$ 57,313

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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+ Details

Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2.	Summary of Significant Accounting Policies

Basis of Presentation

The accompanying Consolidated Financial Statements include the accounts of Trevi Therapeutics, Inc. and its wholly-owned subsidiary Trevi Therapeutics Limited. Intercompany balances and transactions have been eliminated.

All amounts presented are in thousands of dollars, except share and per share amounts, unless noted otherwise. The Company has evaluated events occurring subsequent to December 31, 2020 for potential recognition or disclosure in the Consolidated Financial Statements and concluded there were no subsequent events that required recognition or disclosure other than those provided.

Use of Estimates

The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities at the date of the financial statements and the reported amounts of the expenses during the reporting periods. Significant estimates and assumptions reflected in these Consolidated Financial Statements include, but are not limited to the recognition of research and development expenses (“R&D”) and the valuation of redeemable convertible preferred stock, common stock and stock-based awards. On an ongoing basis, management evaluates its estimates in light of changes in circumstances, facts and experience. Changes in estimates are recorded in the period in which they become known. Actual results could differ from those estimates.

Cash Equivalents

The Company classifies short-term, highly liquid investments with an original term of three months or less at the date of purchase as cash equivalents.

Fair Value Measurements

The Company’s financial instruments have consisted of cash and cash equivalents, tax credit and other receivables, accounts payable, accrued expenses, term loans, term loan derivative liability and obligation for loan success fee (Note 7). Fair value estimates of these instruments are made at a specific point in time, based on relevant market information. The carrying amounts of cash and cash equivalents, tax credit and other receivables, accounts payable and accrued expenses are generally considered to be representative of their respective fair values because of the short-term nature of those instruments. The carrying amount of the term loan approximates its fair value due to its floating market-based interest rate. The fair value of the term loan derivative liability is estimated utilizing a probability-weighted cash flow approach (Note 7). The fair value of the obligation for loan success fee was estimated utilizing a probability-weighted income approach, including variables for the timing of the success event and other probability estimates.

Current accounting guidance defines fair value, establishes a framework for measuring fair value in accordance with Accounting Standards Codification (“ASC”) 820, Fair Value Measurements and Disclosures, and requires certain disclosures about fair value measurements. The valuation techniques included in the guidance are based on observable and unobservable inputs. Observable inputs reflect readily obtainable data from independent sources, while unobservable inputs reflect market assumptions and are classified into the following fair value hierarchy:

Level 1—Observable inputs—quoted prices in active markets for identical assets and liabilities.

Level 2—Observable inputs other than the quoted prices in active markets for identical assets and liabilities—such as quoted prices for similar instruments, quoted prices for identical or similar instruments in inactive markets, or other inputs that are observable or can be corroborated by observable market data.

Level 3—Unobservable inputs—includes amounts derived from valuation models where one or more significant inputs are unobservable and require the company to develop relevant assumptions.

The following table summarizes the financial assets and financial liabilities measured at fair value on a recurring basis as of December 31, 2020 and 2019, and the basis for that measurement, by level within the fair value hierarchy (Note 7). There were no such financial liabilities as of December 31, 2019:

	Level 1		Level 2		Level 3
December 31, 2020
Financial assets carried at fair value:
Money market funds	$	44,095	$	—	$	—

Financial liabilities carried at fair value:
Term loan derivative liability	$	—	$	—	$	196

December 31, 2019
Financial assets carried at fair value:
Money market funds	$	54,593	$	—	$	—

The following table represents a roll-forward of the fair value of Level 3 instruments (significant unobservable inputs):

	December 31,
	2020		2019
Financial liabilities
Balance at beginning of year⁽¹⁾	$	—	$	1,556
Term loan derivative liability		187		—
Unrealized loss on obligation for loan success fee		—		215
Unrealized loss on obligation for term loan derivative		9		—
Net settlements⁽²⁾		—		(1,771	)
Ending balance	$	196	$	—

(1)	The balance at January 1, 2019 relates to the $460 obligation for the loan success fee and the $1,096 fair value of the Series C redeemable convertible preferred stock liability at the time of the third tranche of the Series C Preferred Stock financing in January 2019.

(2)

The net settlements in the year ended December 31, 2019 relate to the $1,096 fair value of the Series C redeemable convertible preferred stock liability at the time of the third tranche of the Series C Preferred Stock financing in January 2019 and the payment of the $675 obligation for the loan success fee in May 2019.

Property, Equipment and Leasehold Improvements

Property, equipment and leasehold improvements (consisting of furniture, computer and office equipment and leasehold improvements) are stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the respective assets (three years for computer equipment, five years for furniture and office equipment, and the shorter of the term of the lease or useful life for leasehold improvements).

Impairment of Long-Lived Assets

ASC 360, Property, Plant, and Equipment, addresses the financial accounting and reporting for impairment or disposal of long-lived assets. The Company reviews the recorded values of long-lived assets for impairment whenever events or changes in business circumstances indicate that the carrying amount of an asset or group of assets may not be fully recoverable. There was no impairment or disposal of long-lived assets during the years ended December 31, 2020 and 2019, respectively.

Foreign Currency Transactions

The Company, at times, contracts with vendors and consultants outside of the United States, resulting in liabilities denominated in foreign currency. The transactions are recorded in U.S. dollars on the transaction dates and any currency fluctuation through the payment date is recorded as currency gains or losses in the Consolidated Statements of Operations. Net foreign currency gains and losses in 2020 and 2019 were insignificant.

Deferred Offering Costs

The Company capitalizes certain legal, professional, accounting and other third-party fees that are directly associated with in-process equity financings as deferred offering costs until such financings are consummated. After consummation of an equity financing, these costs are recorded in stockholders’ equity as a reduction of additional paid-in capital generated as a result of the offering. Should the planned equity financing no longer be considered probable of being consummated, the deferred offering costs are expensed immediately as a charge to operating expenses. Deferred offering costs relating to the Company’s ATM Sales Agreement were $284 as of December 31, 2020, excluding $105, which has been recorded as a reduction to stockholders’ equity in connection with sales under the agreement. The Company’s IPO was completed in May 2019 and IPO costs incurred in 2019 were recorded as a reduction to stockholders’ equity. As a result, deferred offering costs were $0 as of December 31, 2019.

Research and Development Expenses

All of the Company’s research and development expenses consist of expenses incurred in connection with the development of Haduvio. These expenses include certain payroll and personnel expenses, including stock-based compensation, consulting costs, contract manufacturing costs and fees paid to clinical research organizations (“CROs”) to conduct certain research and development activities on the Company’s behalf. The Company does not allocate its costs by each indication for which it is developing Haduvio, as a significant amount of the Company’s development activities broadly support all indications. In addition, several of the Company’s departments support the Company’s Haduvio drug candidate development program and the Company does not identify internal costs for each potential indication. The Company expenses both internal and external research and development expenses as they are incurred.

Accrued Research and Development Expenses

The Company has entered into agreements with CROs, contract manufacturing organizations (“CMOs”) and other companies that provide services in connection with the Company’s research and development activities. The Company’s research and development accruals are estimated based on the level of services performed, progress of the studies, including the phase or completion of events, and contracted costs. The estimated costs of research and development provided, but not yet invoiced, are included in accrued expenses on the Consolidated Balance Sheet. If the actual timing of the performance of services or the level of effort varies from the original estimates, the Company will adjust the accrual accordingly. Payments made to CROs, CMOs and other companies under these arrangements in advance of the performance of the related services are recorded as prepaid expenses or as non-current deposits, as applicable, and are recognized as expenses as the goods are delivered or the related services are performed.

Patent Costs

All patent-related costs in connection with filing and prosecuting patent applications are expensed to general and administrative expense as incurred, as recoverability of such expenditures is uncertain.

Stock-Based Compensation

The Company accounts for stock-based compensation arrangements with employees and non-employees for consultancy services in accordance with ASC 718, Stock Compensation (“ASC 718”). ASC 718 requires the recognition of compensation expense, using a fair value based method, for costs related to all stock-based payments including stock options. The Company’s determination of the fair value of stock options on the date of grant utilizes the Black-Scholes option-pricing model for stock options with time-based vesting, and is impacted by the price of its common stock as well as changes in assumptions regarding a number of complex and subjective variables. These variables include expected term that options will remain outstanding, expected common stock price volatility over the term of the option awards, risk-free interest rates and expected dividends.

The fair value is recognized over the period during which an optionee is required to provide services in exchange for the option award, known as the requisite service period (usually the vesting period) on a straight-line basis. Forfeitures are accounted for as they occur.

Estimating the fair value of equity-settled awards as of the grant date using valuation models, such as the Black-Scholes option pricing model, is affected by assumptions regarding a number of complex variables. Changes in the assumptions can materially affect the fair value and ultimately how much stock-based compensation expense is recognized. These inputs are subjective and generally require analysis and judgment to develop.

Expected Term—The expected term assumption represents the weighted average period that the stock-based awards are expected to be outstanding. The Company has elected to use the “simplified method” for estimating the expected term of the options, whereby the expected term equals the arithmetic average of the vesting term and the original contractual term of the option.

Expected Volatility—For all stock options granted to date, the volatility data was estimated based on a study of publicly traded industry peer companies. For purposes of identifying these peer companies, the Company considered the industry, stage of development, size and financial leverage of potential comparable companies.

Expected Dividend—The Black-Scholes valuation model calls for a single expected dividend yield as an input. The Company currently has no history or expectation of paying cash dividends on its common stock.

Risk-Free Interest Rate—The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues similar in duration to the expected term of the equity-settled award.

Prior to the Company’s IPO in May 2019, the estimated fair value of the common stock underlying the Company’s stock options was determined at each grant date by the Company’s board of directors, with input from management. All options to purchase shares of common stock were intended to be exercisable at a price per share not less than the per share fair value of the Company’s common stock underlying those options on the date of grant.

In the absence of a public trading market for the Company’s common stock prior to the Company’s IPO in May 2019, on each grant date, the Company developed an estimate of the fair value of its common stock based on the information known to the Company on the date of grant, upon a review of any recent events and their potential impact on the estimated fair value per share of the common stock, and in part on input from an independent third-party valuation. As is provided for in Section 409A of the Internal Revenue Code of 1986, as amended (the “Code”), the Company generally relied on valuations for up to twelve months unless the Company had experienced a material event that would have affected the estimated fair value of its common stock.

The valuations of the Company’s common stock performed prior to the Company’s IPO in May 2019, were determined in accordance with the guidelines outlined in the American Institute of Certified Public Accountants Practice Aid, Valuation of Privately-Held-Company Equity Securities Issued as Compensation (the “Practice Aid”). The methodology to determine the fair value of common stock included estimating the fair value of the enterprise using a market approach, which estimates the fair value of the Company by including an estimation of the value of the business based on guideline public companies under a number of different scenarios. The assumptions used to determine the estimated fair value of the Company’s common stock were based on numerous objective and subjective factors, combined with management judgment, including external market conditions affecting the pharmaceutical and biotechnology industry and trends within the industry; the Company’s stage of development; the rights, preferences and privileges of the Company’s convertible preferred stock relative to those of the Company’s common stock; the prices at which the Company sold shares of convertible preferred stock; the Company’s financial condition and operating results, including the Company’s levels of available capital resources; the progress of the Company’s research and development efforts, stage of development and business strategy; equity market conditions affecting comparable public companies; general U.S. market conditions; and the lack of marketability of the Company’s common stock.

The Practice Aid identifies various available methods for allocating enterprise value across classes and series of capital stock to determine the estimated fair value of common stock at each valuation date. In accordance with the Practice Aid, the Company considered the following methods:

•

Option Pricing Method (“OPM”)—The OPM treats common stock and convertible preferred stock as call options on the total equity value of a company, with exercise prices based on the value thresholds at which the allocation among the various holders of a company’s securities changes. Under this method, the common stock has value only if the funds available for distribution to stockholders exceed the value of the liquidation preferences at the time of a liquidity event, such as a strategic sale or merger. The common stock is modeled as a call option on the underlying equity value at a predetermined exercise price. In the model, the exercise price is based on a comparison with the total equity value rather than, as in the case of a regular call option, a comparison with a per share stock price. Thus, common stock is considered to be a call option with a claim on the enterprise at an exercise price equal to the remaining value immediately after the convertible preferred stock liquidation preference is paid. The OPM uses the Black-Scholes option-pricing model to price the call options. This model defines the securities’ fair values as functions of the current fair value of a company and uses assumptions, such as the anticipated timing of a potential liquidity event and the estimated volatility of the equity securities.

•

Probability Weighted Expected Return Method (“PWERM”)—Under the PWERM methodology, the fair value of common stock is estimated based upon an analysis of future values for the company, assuming various outcomes. The common stock value is based on the probability-weighted present value of expected future investment returns considering each of the possible outcomes available as well as the rights of each class of stock. The future value of the common stock under each outcome is discounted back to the valuation date at an appropriate risk-adjusted discount rate and probability weighted to arrive at an indication of value for the common stock.

•

Hybrid Method—The hybrid method is a PWERM where the equity value in one of the scenarios is calculated using an OPM. In the hybrid method used by the Company, it considered an IPO as the other potential future liquidity event. The equity value for the IPO scenario was determined using the guideline public company (“GPC”), method under the market approach. The relative probability of the IPO scenario was determined based on an analysis of market conditions at the time and expectations as to the timing and likely prospects of the IPO at each valuation date. In application of the GPC method, the Company considered publicly traded companies in the biopharmaceutical industry that had a similar profile to the Company’s as well as recently completed IPOs as indicators of estimated future value in an IPO. The Company then discounted that future value back to the valuation date at an appropriate discount rate.

In determining the estimated fair value of the Company’s common stock prior to Company’s IPO in May 2019, the board of directors considered the fact that the Company’s stockholders could not freely trade the Company’s common stock in the public markets. Accordingly, the Company’s board of directors applied discounts to reflect the lack of marketability of common stock based on the weighted-average expected time to liquidity. The estimated fair value of the Company’s common stock at each grant date reflected a non-marketability discount partially based on the anticipated likelihood and timing of a future liquidity event.

Subsequent to the completion of the Company’s IPO in May 2019, the fair value of the Company’s common stock has been determined based on the closing price of the Company’s common stock as reported on the date of grant on the primary stock exchange on which the Company’s common stock is traded.

Income Taxes

The Company accounts for income taxes using the asset and liability method. Under this method, deferred tax assets and liabilities are determined based on differences between the financial reporting and tax bases of assets and liabilities and are measured using the enacted tax rates and laws that will be in effect when the differences are expected to reverse. Deferred income tax assets are reduced, as necessary, by a valuation allowance when management determines it is more likely than not that some or all of the tax benefits will not be realized.

The Company applies the provisions of ASC 740, Income Taxes (“ASC 740”), which prescribes a comprehensive model for how a company should recognize, measure, present, and disclose in its financial statements uncertain tax positions that the company has taken or expects to take on a tax return. These Consolidated Financial Statements reflect expected future tax consequences of such positions presuming the taxing authorities possess full knowledge of the position and all relevant facts. It is the opinion of Company management that there are no material uncertainties regarding the tax positions that the Company has taken through December 31, 2020 and December 31, 2019. The Company does not have any interest or penalties accrued related to tax positions as it does not have any unrecognized tax benefits. In the event the Company determines that accrual of interest or penalties are necessary in the future, the amount will be presented as a component of interest expense.

Redeemable Convertible Preferred Shares

Prior to the Company’s IPO in May 2019, shares of the Company’s redeemable convertible preferred stock were redeemable at the option of the holder on or after July 14, 2020 and carried a cumulative coupon dividend rate of 6%. The redemption amount was the greater of the liquidation value (invested amount plus accruing dividends) or the fair value of the shares of preferred stock on the date of redemption. The Company was accounting for its shares of preferred stock under the requirements of ASC 480, Distinguishing Liabilities from Equity (“ASC 480”), which establishes standards for how an issuer classifies and measures certain financial instruments with characteristics of both liabilities and equity. The carrying value of the shares of preferred stock was presented as temporary equity and was adjusted by periodic accretions so that the carrying amount would equal the redemption amount at the estimated date that the shares of preferred stock would be redeemed. These adjustments were effected through charges against additional paid-in capital, to the extent it was available, or accumulated deficit. For all preferred stock issuances, the difference between the amount invested by the holders of the shares of preferred stock, net of issuance costs and premiums (or discounts), as compared to the redemption value was recorded as accretion over the redemption period of the shares of preferred stock. The accretion was added to net loss to arrive at the net loss available to common stockholders in the calculation of net loss per common share. All redeemable convertible preferred stock shares were converted into common stock as of the date of the Company’s IPO.

Basic and Diluted Net Income (Loss) per Common Share

Basic and diluted net loss per common share outstanding is determined by dividing net loss, as adjusted for accretion and accrued dividends on redeemable convertible preferred stock, by the weighted average common shares outstanding during the period. For all periods presented, outstanding shares of Series A redeemable convertible preferred stock (“Series A Preferred Stock”), shares of Series B redeemable convertible preferred stock (“Series B Preferred Stock”), shares of Series C redeemable convertible preferred stock (“Series C Preferred Stock”), if any, and shares issuable upon exercise of stock options have been excluded from the calculation because their effects would be anti-dilutive. Therefore, the weighted average common shares used to calculate both basic and diluted net loss per share are the same for each of the periods presented.

Segments

The Company has one reporting segment which is also the Company’s only operating segment. Management uses one measurement of profitability and does not segregate its business for internal reporting. All long-lived assets are maintained in the United States.

Recently Adopted Accounting Pronouncements

There have been no new accounting pronouncements adopted during the year ended December 31, 2020.

Recently Issued Accounting Pronouncements

There have been no new accounting pronouncements issued during the year ended December 31, 2020, which could be expected to materially impact the Company’s Consolidated Financial Statements.

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
Document and Entity Information - USD ($) $ in Millions	Dec. 31, 2020	Mar. 24, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Entity Registrant Name	TREVI THERAPEUTICS, INC.
Entity Central Index Key	0001563880
Entity Current Reporting Status	Yes
Entity Voluntary Filers	No
Entity Interactive Data Current	Yes
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Entity Well-known Seasoned Issuer	No
Entity Public Float			$ 41.5
Entity Common Stock, Shares Outstanding		19,914,407
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	TRVI
Security Exchange Name	NASDAQ
Entity File Number	001-38886
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-0834299
Entity Address, Address Line One	195 Church Street
Entity Address, Address Line Two	14th Floor
Entity Address, City or Town	New Haven
Entity Address, State or Province	CT
Entity Address, Postal Zip Code	06510
City Area Code	203
Local Phone Number	304-2499
Document Annual Report	true
Document Transition Report	false
ICFR Auditor Attestation Flag	false
Documents Incorporated by Reference	Portions of the Proxy Statement for the registrant’s 2021 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K.

Summary of Significant Accounting Policies - Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financial liabilities carried at fair value:
Term loan derivative liability	$ 196
Fair Value, Measurements, Recurring [Member] \| Level 1 [Member] \| Money Market Funds [Member]
Financial assets carried at fair value:
Money market funds	44,095	$ 54,593
Fair Value, Measurements, Recurring [Member] \| Level 3 [Member] \| Term Loan Derivative Liability [Member]
Financial liabilities carried at fair value:
Term loan derivative liability	$ 196

Property, Equipment and Leasehold Improvements, Net (Tables)

12 Months Ended

Dec. 31, 2020

Property Plant And Equipment [Abstract]

Summary of Property, Equipment and Leasehold Improvements, Net

Property, equipment and leasehold improvements, net consist of the following:

	As of December 31,
	2020			2019
Computer, website development and office equipment	$	45		$	45
Furniture and fixtures		60			28
Leasehold improvements		130			130
		235			203
Less accumulated depreciation		(132	)		(85	)
	$	103		$	118

Accrued Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Payables And Accruals [Abstract]

Schedule of Accrued Expenses

Accrued expenses consist of the following:

	As of December 31,
	2020		2019
Accrued R&D projects	$	1,754	$	2,084
Accrued consulting and professional fees		560		338
Accrued compensation and benefits		954		776
Other		158		303
	$	3,426	$	3,501

Prepaid Expenses (Tables)

12 Months Ended

Dec. 31, 2020

Prepaid Expense Current [Abstract]

Schedule of Prepaid Expenses

Prepaid expenses consist of the following:

	As of December 31,
	2020		2019
Prepaid R&D payments	$	333	$	1,113
Prepaid corporate insurance		562		491
Other		108		77
	$	1,003	$	1,681

Income Taxes - Reconciliation Between Income Tax Benefit and Expected Tax Benefit at Statutory Rate (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal statutory income tax rate	21.00%	21.00%
State income tax (benefit)—net of federal tax	6.10%	5.90%
Change in valuation allowance	(29.10%)	(28.20%)
Refundable tax credit	0.10%	0.10%
R&D tax credits	2.00%	1.40%
Lease Standard Adoption		(0.10%)
Effective income tax rate	0.10%	0.10%

Stockholders' Equity (Stock-Based Awards) - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
	Jan. 01, 2020	Apr. 30, 2019	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Common stock, capital shares reserved for future issuance			3,646,200	2,778,812
Share based compensation options to purchase no of common stock			2,171,477	1,675,226
Share based compensation options grants in the period			764,583
Weighted average fair value of options granted			$ 3.68	$ 5.06
Fair value of stock options vested			$ 2,200,000	$ 688,000
Fair value of stock options exercised			81,000	$ 105,000
Share-based awards, cost not yet recognized, amount			$ 4,400,000
Share-based award, cost not yet recognized, period for recognition			2 years 6 months
2019 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, award description			As of December 31, 2020 awards may be made under the 2019 Plan for up to such number of shares of the Company’s common stock as is equal to the sum of: i) 1,578,947 shares; plus ii) the number of shares (up to 1,157,894 shares) equal to the number of shares of the Company’s common stock subject to outstanding awards under the 2012 Stock Incentive Plan (the “2012 Plan”) that expire, terminate or are otherwise cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus iii) an annual increase to be added on the first day of each fiscal year, beginning with 2020 and continuing through 2029, equal to the least of (a) 2,105,623 shares of common stock, (b) 4% of the number of outstanding shares of the Company’s common stock on such date, and (c) an amount determined by the Company’s board of directors
Common stock, capital shares reserved for future issuance	713,383		1,578,947
Share based compensation grant period			10 years
Share based compensation vesting description				Options granted under the 2019 Plan and the 2012 Plan have a maximum term of ten years. Options granted to employees, officers and non-employee consultants vest over four years based on varying vesting schedules including: 25% vesting on the first anniversary date of grant and the balance ratably over the next 36 months or vesting in equal monthly or quarterly installments over four years. Options granted to directors generally vest over up to one to two years.
Share based compensation options to purchase no of common stock			1,249,653	631,234
2019 Stock Incentive Plan [Member] \| Employees, Officers and Non-employee Consultants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting period			4 years
2019 Stock Incentive Plan [Member] \| Employees, Officers and Non-employee Consultants [Member] \| Vesting First Anniversary Date of Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting Percentage			25.00%
2019 Stock Incentive Plan [Member] \| Minimum [Member] \| Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting period			1 year
2019 Stock Incentive Plan [Member] \| Maximum [Member] \| Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting period			2 years
2019 Stock Incentive Plan [Member] \| Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in additional number of shares to be issued	2,105,623
Percentage of number of common stock, shares outstanding	4.00%
2012 Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation grant period			10 years
Share based compensation vesting description				Options granted under the 2019 Plan and the 2012 Plan have a maximum term of ten years. Options granted to employees, officers and non-employee consultants vest over four years based on varying vesting schedules including: 25% vesting on the first anniversary date of grant and the balance ratably over the next 36 months or vesting in equal monthly or quarterly installments over four years. Options granted to directors generally vest over up to one to two years.
Share based compensation options to purchase no of common stock			921,824	1,043,992
2012 Stock Incentive Plan [Member] \| Stock Option [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation options grants in the period			0
2012 Stock Incentive Plan [Member] \| Other Equity-Based Award [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation options grants in the period			0
2012 Stock Incentive Plan [Member] \| Employees, Officers and Non-employee Consultants [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting period			4 years
2012 Stock Incentive Plan [Member] \| Employees, Officers and Non-employee Consultants [Member] \| Vesting First Anniversary Date of Grant [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting Percentage			25.00%
2012 Stock Incentive Plan [Member] \| Minimum [Member] \| Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting period			1 year
2012 Stock Incentive Plan [Member] \| Maximum [Member] \| Director [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation vesting period			2 years
2012 Stock Incentive Plan [Member] \| Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation options to purchase number of shares outstanding			1,157,894
2019 Employee Stock Purchase Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, award description			The number of shares of the Company’s common stock that have been approved to be issued under the 2019 ESPP is equal to the sum of: i) 155,106 shares; plus ii) an annual increase to be added on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2020 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2029, equal to the least of (a) 526,315 shares of common stock, (b) 1% of the number of outstanding shares of the Company’s common stock on such date, and (c) an amount determined by the Company’s board of directors. The aggregate number of shares of the Company’s common stock that may be issued under the 2019 ESPP increased, pursuant to the terms of the 2019 ESPP, by an additional 178,345 shares, equal to 1% of the Company’s then-outstanding common stock, effective as of January 1, 2020.
Common stock, capital shares reserved for future issuance		155,106
Stock-based compensation expense			$ 5,000	$ 0
2019 Employee Stock Purchase Plan [Member] \| Common Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Increase in additional number of shares to be issued	178,345	526,315
Percentage of number of common stock, shares outstanding	1.00%	1.00%

Retirement Plan and Other Employee Benefits - Additional Information (Detail) - USD ($) $ in Thousands		12 Months Ended
	Mar. 31, 2013	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Matching contributions, percent	50.00%
Defined contribution plan elective contributions percent of match	6.00%
Defined contribution plan, vesting period	4 years
Defined contribution plan, employers matching contribution, annual vesting percentage	25.00%
Defined contribution plan employers matching contribution compliance with regulatory capital requirements		$ 68	$ 111
Cost incurred for health care and life insurance benefits		$ 407	$ 289

Debt - Additional Information (Detail)			1 Months Ended	12 Months Ended
Debt - Additional Information (Detail)	Aug. 13, 2020 USD ($) Installment	Dec. 29, 2014 USD ($)	May 31, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Aug. 31, 2020 USD ($)
Interest expense				$ 456,000
Carrying value of outstanding term loan				13,954,000
Loan success fee payable			$ 675,000			$ 460,000
Fair value of success fee liabilities				0	$ 0
Non cash charges				0	215,000
SVB Term Loan [Member]
Debt instrument, principal amount	$ 14,000,000			$ 14,000,000
Interest-only payment period	24 months
Loan payment, number of consecutive equal monthly installments of principal including accrued interest \| Installment	24
Debt instrument, maturity date				Feb. 01, 2024
Debt instrument, final payment fee amount	$ 1,200,000			$ 1,200,000
Debt instruments percentage of required to deposit unrestricted and unencumbered cash collateral	100.00%
Equity raise requirements, description				If the Company fails to meet certain equity raise requirements under the SVB Loan Agreement, it will be required to deposit unrestricted and unencumbered cash equal to 100% of the principal amount of the SVB Term Loan then outstanding in a cash collateral account with SVB, which can be used by SVB to prepay the SVB Term Loan at any time.
Debt default additional interest charge	5.00%
Debt finance costs							$ 57,000
Amortization of deferred financing charges				$ 9,000
Unamortized deferred charges				48,000
Financing costs paid							$ 27,000
Accretion loan discounts				4,000
Loan discounts-financing costs				23,000
Debt instrument, accrued final payment fee				$ 183,000
Contingent interest rate increase				2.00%
Fair value of liabilities				$ 9,000
Amortization of term loan				29,000
Term loan discount interest				158,000
Interest expense				456,000	0
Carrying value of outstanding term loan				13,954,000	0
SVB Term Loan [Member] \| Term Loan Derivative Liability [Member]
Term loan derivative liability	$ 187,000			$ 196,000
SVB Term Loan [Member] \| Term Loan Derivative Liability [Member] \| Contingent Interest Rate Increase [Member]
Derivative liability, measurement input				0.0200
SVB Term Loan [Member] \| Term Loan Derivative Liability [Member] \| Discount Rate [Member]
Derivative liability, measurement input				0.120
SVB Term Loan [Member] \| Minimum [Member]
Interest rate, floating	4.25%
Long term debt percentage bearing adjusted floating interest rate	6.25%
SVB Term Loan [Member] \| Prepayment Prior to First Anniversary of Effective Date [Member]
Prepayment premium percentage on principal amount	3.00%
SVB Term Loan [Member] \| Prepayment After First Anniversary of Effective Date and Prior To Second Anniversary of Effective Date [Member]
Prepayment premium percentage on principal amount	2.00%
SVB Term Loan [Member] \| Prepayment After Second Anniversary of the Effective Date and Prior to February 1, 2024 [Member]
Prepayment premium percentage on principal amount	1.00%
Solar Capital Term Loan [Member]
Debt instrument, principal amount		$ 15,000,000
Debt instrument, outstanding amount				$ 0	$ 0
Loan success fee, as percentage of term loan funded		4.50%
Solar Capital Term Loan A [Member]
Loan success fee payable			$ 675,000
Prime Rate [Member] \| SVB Term Loan [Member]
Variable interest rate	1.00%
Adjusted Prime Rate [Member] \| SVB Term Loan [Member]
Variable interest rate	3.00%

Property, Equipment and Leasehold Improvements, Net - Summary of Property, Equipment and Leasehold Improvements, Net (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements	$ 235	$ 203
Less accumulated depreciation	(132)	(85)
Property, equipment and leasehold improvements, net	103	118
Computer, Website Development And Office Equipment [Member]
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements	45	45
Furniture And Fixtures [Member]
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements	60	28
Leasehold Improvements [Member]
Property Plant And Equipment [Line Items]
Property, equipment and leasehold improvements	$ 130	$ 130

Leases - Additional Information (Detail) $ in Thousands		12 Months Ended
Leases - Additional Information (Detail) $ in Thousands	Mar. 01, 2018 USD ($) ft²	Dec. 31, 2020 USD ($) Lease	Dec. 31, 2019 USD ($) Lease
Operating lease, weighted average discount rate, percent		13.00%
Number of new leases \| Lease		0	0
Remaining terms		2 years 3 months
Operating Lease, Payments		$ 138	$ 125
Building [Member]
Leased spaced area \| ft²	5,600
Operating lease term	60 months
Building [Member] \| Minimum [Member]
Operating lease rent expense	$ 10
Building [Member] \| Maximum [Member]
Operating lease rent expense	$ 11
Office Equipment [Member]
Operating lease rent expense		$ 124	$ 124

Property, Equipment and Leasehold Improvements, Net - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Depreciation	$ 47	$ 39

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating expenses:
Research and development	$ 22,328	$ 19,339
General and administrative	10,161	7,306
Total operating expenses	32,489	26,645
Loss from operations	(32,489)	(26,645)
Other income (expense):
Change in fair value of obligation for loan success fee		(215)
Change in fair value of term loan derivative liability	(9)
Interest income	178	792
Interest expense	(456)
Total other income (expense), net	(287)	577
Loss before income tax benefit	(32,776)	(26,068)
Income tax benefit	18	18
Net loss	(32,758)	(26,050)
Accretion of redeemable convertible preferred stock		1,535
Dividends accrued on redeemable convertible preferred stock		(2,239)
Adjusted net loss attributable to common stockholders	$ (32,758)	$ (26,754)
Basic and diluted net loss per common share outstanding	$ (1.81)	$ (2.28)
Weighted average common shares used in net loss per share attributable to common stockholders, basic and diluted	18,059,011	11,735,781

Subsequent Events

12 Months Ended

Dec. 31, 2020

Subsequent Events [Abstract]

Subsequent Events

14.	Subsequent Events

Subsequent to December 31, 2020, and through March 24, 2021, the Company had issued and sold an additional 1,367,621 shares of common stock for gross proceeds of $4.4 million, before deducting estimated commissions and allocated fees of $0.3 million under the ATM Sales Agreement (Note 8).

Accrued Expenses - Schedule of Accrued Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued R&D projects	$ 1,754	$ 2,084
Accrued consulting and professional fees	560	338
Accrued compensation and benefits	954	776
Other	158	303
Total Accrued expenses	$ 3,426	$ 3,501

Leases - Schedule of Balance Sheet Operating Leases (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Operating lease right-of-use asset	$ 227	$ 312
Liabilities:
Operating lease liabilities, current portion	113	99
Operating lease liabilities, long term portion	144	257
Total operating lease liabilities	$ 257	$ 356

Stockholders' Equity - Stock-based Compensation Expenses (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Stock-based compensation	$ 2,417	$ 1,127
Research and Development Expense [Member]
Stock-based compensation	360	143
General and Administrative Expense [Member]
Stock-based compensation	$ 2,057	$ 984

Retirement Plan and Other Employee Benefits

12 Months Ended

Dec. 31, 2020

Compensation And Retirement Disclosure [Abstract]

Retirement Plan and Other Employee Benefits

13.	Retirement Plan and Other Employee Benefits

Savings Plan

In March 2013, the Company adopted and became a participating employer of a multiple employer defined contribution retirement plan that complies with Section 401(k) of the Code. All eligible employees of the Company immediately participate in the plan (with an entry date of the first day of any month), with no minimum service requirement. The 401(k) plan provides that the Company make non-discretionary matching contributions of 50% of the first 6% of elective contributions. Participants are immediately vested in their contributions, as well as any earnings thereon. Vesting in the employer match contribution portion of their accounts, as well as any earnings thereon, is based on years of credited service, vesting over a four-year period, with 25% vesting per completed year. The Company’s expense under the 401(k) plan, representing its employer matching contributions and additional contributions in accordance with regulatory compliance requirements, totaled $68 and $111 in the years ended December 31, 2020 and 2019, respectively.

Health Care and Life Insurance Benefits

The Company offers health care and life insurance benefits to all eligible and active employees. Costs incurred for these benefits totaled $407 and $289 during the years ended December 31, 2020 and 2019, respectively.

Stockholders’ Equity

12 Months Ended

Dec. 31, 2020

Stockholders Equity Note [Abstract]

Stockholders' Equity

8.	Stockholders’ Equity

Preferred Stock

As of December 31, 2020 and 2019, the Company’s restated certificate of incorporation authorized the Company to issue 5,000,000 shares of preferred stock.

Common Stock

As of December 31, 2020 and 2019, the Company’s restated certificate of incorporation authorized the Company to issue 200,000,000 shares of common stock, with a par value of $0.001 per share.

As of December 31, 2020 and 2019, the Company had reserved 3,646,200 and 2,778,812 shares of common stock, respectively, for the exercise of outstanding stock options and the number of shares of common stock remaining available for future stock-based awards under the Company’s 2012 Stock Incentive Plan, 2019 Stock Incentive Plan and 2019 Employee Stock Purchase Plan, as shown in the table below:

	As of December 31,
	2020		2019
Shares of common stock reserved for future issuance under the 2012 Stock Incentive Plan		921,824		1,043,992
Shares of common stock reserved for future issuance under the 2019 Stock Incentive Plan		2,396,922		1,579,714
Shares of common stock reserved for future issuance under the 2019 Employee Stock Purchase Plan		327,454		155,106
		3,646,200		2,778,812

Initial Public Offering and Concurrent Private Placement

On May 9, 2019, the Company completed its IPO and a concurrent private placement in which it issued and sold an aggregate of 7,000,000 shares of common stock at an offering price of $10.00 per share, for net proceeds of $62.1 million, after deducting aggregate underwriting discounts and commissions and private placement agent fees of $4.9 million and other offering expenses of $3.0 million. The Company’s common stock began trading on The Nasdaq Global Market on May 7, 2019 under the ticker symbol “TRVI”.

At-the-Market Offering

In June 2020, the Company entered into the ATM Sales Agreement with SVB Leerink LLC, under which the Company may issue and sell shares of its common stock, from time to time, having an aggregate offering price of up to $12.0 million. Sales of common stock under the ATM Sales Agreement may be made by any method that is deemed an “at the market” offering as defined in Rule 415(a)(4) under the Securities Act of 1933, as amended. The Company is not obligated to make any sales of its common stock under the ATM Sales Agreement. The Company began making sales pursuant to the ATM Sales Agreement in July 2020, and as of December 31, 2020, the Company had issued and sold an aggregate of 687,876 shares of common stock for gross proceeds of $3.2 million, before deducting estimated commissions and allocated fees of $0.2 million.

Stock Based Awards

In April 2019, the Company’s board of directors adopted the 2019 Stock Incentive Plan (the “2019 Plan”), which became effective on May 7, 2019. The 2019 Plan provides for the grant of incentive stock options, nonstatutory stock options, stock appreciation rights, restricted stock awards, restricted stock units and other stock-based awards. The Company’s employees, officers, directors, consultants and advisors are eligible to receive awards under the 2019 Plan. The 2019 Plan is administered by the Company’s board of directors.

As of December 31, 2020 awards may be made under the 2019 Plan for up to such number of shares of the Company’s common stock as is equal to the sum of: i) 1,578,947 shares; plus ii) the number of shares (up to 1,157,894 shares) equal to the number of shares of the Company’s common stock subject to outstanding awards under the 2012 Stock Incentive Plan (the “2012 Plan”) that expire, terminate or are otherwise cancelled, forfeited or repurchased by the Company at their original issuance price pursuant to a contractual repurchase right; plus iii) an annual increase to be added on the first day of each fiscal year, beginning with 2020 and continuing through 2029, equal to the least of (a) 2,105,623 shares of common stock, (b) 4% of the number of outstanding shares of the Company’s common stock on such date, and (c) an amount determined by the Company’s board of directors. The number of shares reserved for issuance under the 2019 Plan increased, pursuant to the terms of the 2019 Plan, by an additional 713,383 shares, equal to 4% of the Company’s then-outstanding common stock, effective as of January 1, 2020.

The 2012 Plan was adopted by the Company’s board of directors and stockholders. The Company’s board of directors administers the 2012 Plan. The 2012 Plan provides for the issuance of stock-based awards to the Company’s employees, officers and directors, as well as non-employee/consultants and advisors to the Company.

Options granted under the 2019 Plan and the 2012 Plan have a maximum term of ten years. Options granted to employees, officers and non-employee consultants vest over four years based on varying vesting schedules including: 25% vesting on the first anniversary date of grant and the balance ratably over the next 36 months or vesting in equal monthly or quarterly installments over four years. Options granted to directors generally vest over up to one to two years. As of December 31, 2020 and 2019, respectively, options to purchase 1,249,653 and 631,234 shares of common stock were granted and outstanding, net of cancelations, under the 2019 Plan. As of December 31, 2020 and 2019, respectively, options to purchase 921,824 and 1,043,992 shares of common stock were granted and outstanding, net of cancelations, under the 2012 Plan.

In April 2019, the Company’s board of directors adopted a resolution effective on May 7, 2019 that no further stock options or other equity-based awards may be granted under the 2012 Plan.

A summary of the Company’s combined stock option activity for the 2019 Plan and the 2012 Plan for the year ended December 31, 2020 is as follows:

	Number of Option Shares			Weighted Average Exercise Price		Weighted Average Contractual Term		Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding as of December 31, 2019		1,675,226		$	6.20		7.8	$	864
Granted		764,583			5.11
Forfeited		(163,463	)		7.77
Expired		(86,526	)		9.18
Exercised		(18,343	)		1.82
Outstanding as of December 31, 2020		2,171,477		$	5.62		7.5	$	185
Options exercisable as of December 31, 2020		1,009,847		$	4.67		6.0	$	185
Options unvested as of December 31, 2020		1,161,630		$	6.44		8.8	$	—

The weighted average grant-date fair value per share of stock options granted was $3.68 and $5.06 for the years ended December 31, 2020 and 2019, respectively.

The aggregate fair value of stock options that vested during the years ended December 31, 2020 and 2019 was $2.2 million and $688, respectively.

The aggregate intrinsic value of stock options is calculated as the difference between the exercise price of the stock options and the fair value of the Company’s common stock for those stock options that had exercise prices lower than the fair value of the Company’s common stock. The aggregate intrinsic value of stock options exercised during the years ended December 31, 2020 and 2019 was $81 and $105, respectively.

The assumptions that the Company used to determine the fair value of the stock options granted were as follows, presented on a weighted average basis:

	Year Ended December 31,
	2020			2019
Risk-free interest rate		1.2	%		2.0	%
Expected volatility		81.5	%		78.7	%
Expected dividend yield		—			—
Expected life of options (in years)		6.8			6.8

In April 2019, the Company’s board of directors adopted the 2019 Employee Stock Purchase Plan (the “2019 ESPP”), which became effective on May 7, 2019. The 2019 ESPP is administered by the Company’s board of directors. The Company recognized $5 of stock-based compensation expense for the 2019 ESPP during the year ended December 31, 2020. During the year ended December 31, 2019, there was no activity under the 2019 ESPP.

The number of shares of the Company’s common stock that have been approved to be issued under the 2019 ESPP is equal to the sum of: i) 155,106 shares; plus ii) an annual increase to be added on the first day of each fiscal year, beginning with the fiscal year ending December 31, 2020 and continuing for each fiscal year until, and including, the fiscal year ending December 31, 2029, equal to the least of (a) 526,315 shares of common stock, (b) 1% of the number of outstanding shares of the Company’s common stock on such date, and (c) an amount determined by the Company’s board of directors. The aggregate number of shares of the Company’s common stock that may be issued under the 2019 ESPP increased, pursuant to the terms of the 2019 ESPP, by an additional 178,345 shares, equal to 1% of the Company’s then-outstanding common stock, effective as of January 1, 2020.

All of the Company’s employees are eligible to participate in the 2019 ESPP, provided that:

•

such person is customarily employed by the Company for more than 20 hours a week and for more than five months in a calendar year;

•

such person has been employed by the Company for at least three months prior to enrolling in the 2019 ESPP; and

•

such person was an employee of the Company on the first day of the applicable offering period under the 2019 ESPP.

The following table summarizes the classifications of stock-based compensation expenses for the 2012 Plan, the 2019 Plan and the 2019 ESPP recognized in the Consolidated Statements of Operations:

	Year Ended December 31,
	2020		2019
Research and development expense	$	360	$	143
General and administrative expense		2,057		984
	$	2,417	$	1,127

As of December 31, 2020, total unrecognized compensation cost related to the unvested share-based awards was $4.4 million, which is expected to be recognized over a weighted average period of 2.5 years.

Redeemable Convertible Preferred Stock

Upon the closing of the IPO, the Company’s outstanding redeemable convertible preferred stock, including the accrued dividends thereon, automatically converted into an aggregate of 10,381,234 shares of the Company’s common stock. Upon such conversion of the redeemable convertible preferred stock, the Company reclassified the carrying values of the redeemable convertible preferred stock to common stock and additional paid-in capital.

Prior to the conversion into common stock as noted above, the Company’s redeemable convertible preferred stock was redeemable on or after July 14, 2020 and carried a cumulative coupon dividend rate of 6%. The redemption amount per share for a share of redeemable convertible preferred stock was the greater of (A) the applicable original issue price per share for such series of redeemable convertible preferred stock, plus any of the dividends accrued but unpaid thereon, whether or not declared, together with any other dividends declared but unpaid thereon, and (B) the fair market value per share of redeemable convertible preferred stock, as described below under Redemption Rights. The Company accounted for its redeemable convertible preferred stock under the requirements of ASC 480, which establishes standards for how an issuer classifies and measures certain financial instruments with characteristics of both liabilities and equity. The carrying value of the redeemable convertible preferred stock was presented as temporary equity and was adjusted by periodic accretions so that the carrying amount equaled the redemption amount at the estimated date that the redeemable convertible preferred stock would be redeemed. These adjustments were effected through charges against additional paid-in capital, to the extent it was available, or accumulated deficit. For all issuances of redeemable convertible preferred stock, the difference between the amount invested by the holders of the redeemable convertible preferred stock, net of issuance costs and premiums (or discounts), as compared to the redemption value, was recorded as accretion over the redemption period of the redeemable convertible preferred stock. The accretion was added to net loss to arrive at the net loss available to common stockholders in the calculation of net loss per common share.

Issuance of Series A Redeemable Convertible Preferred Stock

On December 4, 2012, the Company entered into the Series A Preferred Stock Purchase Agreement (the “Series A Purchase Agreement”) with TPG Biotechnology Partners III, L.P. (“TPG”) and nine other holders of the Company’s convertible notes that were issued in 2011 and 2012 (the “Series A Investors”). Pursuant to the Series A Purchase Agreement, the Company issued 6,000,000 shares (the “Series A Initial Closing”) of Series A Preferred Stock to TPG at a purchase price of $1.00 per share, resulting in proceeds, net of $128 in issuance costs, of $5.9 million (the “Series A Financing”). Concurrently, convertible notes held by the Series A Investors totaling $564, including accrued interest, were automatically converted at a conversion price of $0.467 per share in accordance with calculations specified in the applicable note purchase agreement, and the Company issued 1,207,923 shares of Series A Preferred Stock in settlement of the convertible notes.

The Series A Purchase Agreement also provided for the sale of 4,000,000 additional shares of Series A Preferred Stock (the “Series A Milestone Shares”) to TPG at a purchase price of $1.00 per share upon the Company’s achievement of specified Milestone Events, as defined in the Series A Purchase Agreement, involving the Company’s Phase 1b clinical trial in uremic pruritus and a pending patent application. In the event the Milestone Events were not achieved, TPG had the right to purchase the Series A Milestone Shares, in full or in part, under the same terms and conditions as the Series A Initial Closing, including the $1.00 per share purchase price, on or before June 30, 2014.

In addition, TPG had the right to purchase, under the same terms and conditions as the Series A Initial Closing, including the $1.00 per share purchase price, the lesser of 2,500,000 additional shares of Series A Preferred Stock (the “Additional Series A Preferred Shares”) and the number of shares of Series A Preferred Stock equal to 25% of the total number of shares of Series A Preferred Stock it previously purchased for cash under the Series A Purchase Agreement. This additional right was exercisable until the date six months after the completion date of the Company’s Phase 2b/3 clinical trial of Haduvio in patients with uremic pruritus.

On December 26, 2013, TPG purchased under a Series A Extension Preferred Stock Purchase Agreement (the “Series A Extension Purchase Agreement”) 6,500,000 additional shares of Series A Preferred Stock at $1.00 per share, which consisted of the Series A Milestone Shares and the Additional Series A Preferred Shares discussed above, resulting in proceeds, net of $39 in issuance costs, of $6.5 million. This agreement also provided that the Company could sell up to 2,000,000 additional shares at $1.00 per share to existing stockholders deemed accredited investors within 45 days of the December 26, 2013 closing.

In January 2014, the Company issued 1,680,000 shares of Series A Preferred Stock to eight of the Series A Investors at $1.00 per share, as provided for as Additional Closings under the Series A Extension Purchase Agreement, resulting in proceeds, net of $7 in issuance costs, of $1.7 million. The Company recorded this issuance at its fair value of $1.08 per share, totaling $1.8 million before financing costs, resulting in a discount on this issuance in the amount of $134, which amount was being amortized out of the carrying value of Series A Preferred Stock over the expected redemption period, which was three years from July 14, 2017, the date of the First Tranche Closing of the Series C Preferred Stock Financing (each such term as defined below), or July 14, 2020 (the “Redemption Period”). Such amortization totaled $7 for the year ended December 31, 2019 which includes $5 of previously unaccreted discount on issuance at the time of conversion to shares of common stock. There was no such amortization for the year ended December 31, 2020.

Holders of Series C Preferred Stock had a higher liquidation preference than the holders of Series A Preferred Stock and Series B Preferred Stock. (See Liquidation Preferences note below.)

Issuance of Series B Redeemable Convertible Preferred Stock

On May 23, 2014, the Company entered into the Series B Preferred Stock Purchase Agreement (the “Series B Purchase Agreement”) with TPG. Pursuant to the Series B Purchase Agreement, the Company issued 13,043,478 shares (the “Series B Initial Closing”) of Series B Preferred Stock to TPG at a purchase price of $1.15 per share, resulting in proceeds, net of $56 in issuance costs, of $15.0 million.

The Series B Purchase Agreement also provided for the sale of 4,347,826 additional shares of Series B Preferred Stock (the “Series B Milestone Shares”) to TPG at a purchase price of $1.15 per share upon the Company’s achievement of specified Milestone Events, as defined in the Series B Purchase Agreement, involving the Company’s Phase 2b/3 clinical trial of Haduvio in patients with uremic pruritus; its planned Phase 2 clinical trial of Haduvio in patients with pruritus associated with prurigo nodularis; and a pending patent application. In the event the Milestone Events were not achieved, TPG had the right to purchase the Series B Milestone Shares, in full or in part, under the same terms and conditions as the Series B Initial Closing, at a purchase price of $1.15 per share, on or before November 30, 2015.

In addition, TPG had the right to purchase, on the same terms and conditions as the Series B Initial Closing, including the $1.15 per share purchase price, the lesser of 4,347,826 additional shares of Series B Preferred Stock and the number of shares equal to 25% of the total number of shares it previously purchased for cash under the Series B Purchase Agreement (the “Additional Series B Shares”). This additional right was exercisable until the date six months after the completion date of the Company’s Phase 2b/3 clinical trial of Haduvio in patients with uremic pruritus.

On October 30, 2014, TPG exercised its rights described above and purchased under an Additional Closing Agreement (the “Series B Second Closing”) 8,695,652 additional shares of Series B Preferred Stock at $1.15 per share, which consisted of the Series B Milestone Shares and the Additional Series B Shares. This agreement also provided for the Company to sell 869,565 additional shares of Series B Preferred Stock at $1.15 per share to an existing stockholder. The Series B Second Closing resulted in proceeds, net of $19 in issuance costs, of $11.0 million. The Company recorded this issuance at its fair value of $1.10 per share, totaling $10.5 million, net of financing costs, resulting in a premium on this issuance in the amount of $478 which amount was being accreted into the carrying value of the Series B Preferred Stock over the Redemption Period. Such accretion totaled $31 for the year ended December 31, 2019 which includes $22 of unaccreted premium on issuance at the time of conversion to shares of common stock. There was no such accretion for the year ended December 31, 2020.

Holders of Series C Preferred Stock had a higher liquidation preference than the holders of Series A Preferred Stock and Series B Preferred Stock. (See Liquidation Preferences note below.)

Issuance of Series C Redeemable Convertible Preferred Stock

On July 14, 2017, the Company entered into the Series C Purchase Agreement with TPG and other institutional investors (the “Series C Initial Purchasers”) for the issuance of $50.5 million of its Series C Preferred Stock. The Series C Purchase Agreement provided for the Company’s Series C Preferred Stock to be issued in two tranches, with the closing of the first tranche on July 14, 2017 (the “First Tranche Closing”) and the closing of the second tranche to occur following a determination by the Company’s board of directors that the Company’s cash and cash equivalents at such time are not sufficient to fund its operations for a period of three months following such determination (the “Second Tranche Closing”). Upon the First Tranche Closing, the Company issued 20,547,946 shares of its Series C Preferred Stock at a purchase price of $1.46 per share, resulting in proceeds of $29.7 million, net of issuance costs of $291.

Also party to the Series C Purchase Agreement were eleven holders of the Company’s Convertible Notes (together with the Initial Purchasers and the Series C Additional Purchasers, as defined below, the “Series C Investors”). Concurrently with the First Tranche Closing and pursuant to the Series C Purchase Agreement, the outstanding principal on the Company’s Convertible Notes, totaling $10.6 million, and all accrued interest thereon, totaling $564, were automatically converted at the Mandatory Conversion Price of $1.095 per share, and the Company issued 10,181,233 shares of its Series C Preferred Stock in full settlement of the Convertible Notes.

The Series C Purchase Agreement provided for a subsequent closing (the “Special Closing”), on the same terms and conditions as the First Tranche Closing, including the $1.46 per share purchase price, and on October 11, 2017, the Special Closing occurred, resulting in the issuance to two additional investors (the “Series C Additional Purchasers”) of 101,707 shares of the Company’s Series C Preferred Stock, at a purchase price of $1.46 per share, resulting in proceeds of $129, net of issuance costs of $19.

On November 12, 2017, one of the Series C Additional Purchasers purchased its second tranche shares pursuant to an election under the Series C Purchase Agreement, resulting in the issuance of 55,621 shares of the Company’s Series C Preferred Stock at a purchase price of $1.46 per share, resulting in proceeds of $81.

On August 28, 2018, the Company amended the Series C Purchase Agreement to provide that a portion of the shares of Series C Preferred Stock that would otherwise be issued and sold at the Second Tranche Closing would instead be issued and sold at a third tranche closing (the “Third Tranche Closing”), with such closing to occur following a determination by the Company’s board of directors that the Company’s cash and cash equivalents at such time are not sufficient to fund its operations for a period of three months following such determination.

On August 30, 2018, the Company completed the Second Tranche Closing, resulting in the issuance of 7,211,165 shares of the Company’s Series C Preferred Stock, at a purchase price of $1.46 per share, resulting in proceeds of $10.5 million, net of issuance costs of $32.

On January 18, 2019, the Company completed the Third Tranche Closing, resulting in the issuance of 6,849,315 shares of the Company’s Series C Preferred Stock, at a purchase price of $1.46 per share, resulting in proceeds of $10.0 million, net of issuance costs of $37. At such time, the Series C redeemable convertible preferred stock liability of $1.1 million was reclassified as Series C Preferred Stock.

Series C Redeemable Convertible Preferred Stock Liability and Changes in Fair Value

As discussed above, the Series C Purchase Agreement provided for the issuance and sale of Series C Preferred Stock in three separate tranches. The tranches represented a freestanding financial instrument under ASC 480 and required fair value accounting until they were settled. The Company recognized a liability on its Consolidated Balance Sheet for the obligations under this financial instrument. The Company adjusted this liability to fair value at each reporting date, as applicable, and recognized any changes in fair value of the Series C Preferred Stock in its Consolidated Statements of Operations as a component of other income (expense). The Company continued to recognize any changes in the fair value of this liability through the closing of the third tranche.

Accordingly, for the year ended December 31, 2018, the Company recorded the Series C redeemable convertible preferred stock liability at its fair value of $2.1 million, with a corresponding charge to other income (expense) in the Company’s Consolidated Statement of Operations. Upon the Second Tranche Closing in August 2018, as described above, $1.0 million was reclassified to Series C Preferred Stock. As a result, at December 31, 2018, the fair value of this liability, relating to the outstanding third tranche, was determined to be $1.1 million and was reclassified to Series C Preferred Stock upon the Third Tranche Closing in January 2019.

The fair value of the Series C redeemable convertible preferred stock liability was estimated as the excess, if any, of the fair value per share of the Company’s Series C Preferred Stock, as described below under Redemption Rights, over the purchase price of any outstanding tranches to be sold pursuant to the Series C Purchase Agreement.

Holders of Series C Preferred Stock had a higher liquidation preference than the holders of Series A Preferred Stock and Series B Preferred Stock. (See Liquidation Preferences note below.)

As of December 31, 2020 and 2019, there were no shares of redeemable convertible preferred stock outstanding as a result of the conversion into common stock in connection with the IPO.

Dividends

Dividends on outstanding shares of Series A, Series B and Series C Preferred Stock accrued at a rate of 6% per annum on their original purchase price of $1.00, $1.15 and $1.46 per share, respectively (the “Accruing Dividends”), whether or not declared, and were cumulative. However, Accruing Dividends on the Company’s outstanding redeemable convertible preferred stock were payable only when, as and if declared by the Company’s board of directors, or upon liquidation, redemption or conversion. No dividends were payable to the holders of the Company’s common stock unless equivalent dividends had been declared and paid on the Company’s outstanding Series A, Series B and Series C Preferred Stock. No dividends had been declared or paid by the Company through the date of the IPO. Accruing Dividends totaled $18.4 million through the date of the IPO, at which time they were converted into common shares.

Liquidation Preferences

In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or deemed liquidation event, the holders of shares of Series C Preferred Stock then outstanding were entitled to be paid out of the assets of the Company that were available for distribution to its stockholders, before any payments were to be made to the holders of Series A Preferred Stock, Series B Preferred Stock or common stock by reason of their ownership thereof, an amount per share equal to the Series C Preferred Stock original issue price of $1.46 per share, plus any Accruing Dividends accrued but unpaid thereon, whether or not declared, together with any other dividends declared but unpaid thereon. If upon any such liquidation, dissolution or winding up of the Company or deemed liquidation event, the assets of the Company available for distribution to its stockholders were insufficient to pay the holders of shares of Series C Preferred Stock the full amount to which they were entitled, the holders of Series C Preferred Stock were entitled to share ratably in any distribution of the assets available for distribution in proportion to the respective amounts which would otherwise be payable in respect of the shares of Series C Preferred Stock held by them upon such distribution if all amounts payable on or with respect to such shares were paid in full.

In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or deemed liquidation event, the holders of shares of Series A Preferred Stock and Series B Preferred Stock then outstanding were entitled to be paid out of the assets of the Company available for distribution to its stockholders after the payment of all preferential amounts required to be paid to the holders of shares of Series C Preferred Stock but before any payments were made to the holders of common stock by reason of their ownership thereof, (i) an amount per share equal to the Series A original issue price of $1.00 per share in the case of the Series A Preferred Stock, plus any Accruing Dividends accrued but unpaid thereon, whether or not declared, together with any other dividends declared but unpaid thereon, and (ii) an amount per share equal to the Series B original issue price of $1.15 per share in the case of the Series B Preferred Stock, plus any Accruing Dividends accrued but unpaid thereon, whether or not declared, together with any other dividends declared but unpaid thereon. If upon any such liquidation, dissolution or winding up of the Company or deemed liquidation event, the assets of the Company available for distribution to its stockholders were insufficient to pay the holders of shares of Series A Preferred Stock and Series B Preferred Stock the full amount to which they were entitled (after the payment in full of all preferential amounts required to be paid to the holders of shares of Series C Preferred Stock), the holders of shares of Series A Preferred Stock and Series B Preferred Stock were entitled to share ratably in any distribution of the assets available for distribution in respect of such shares in proportion to the respective amounts which would otherwise be payable in respect of the share of Series A Preferred Stock and Series B Preferred Stock held by them upon such distribution if all amounts payable on or with respect to such shares were paid in full.

In the event of any voluntary or involuntary liquidation, dissolution or winding up of the Company or deemed liquidation event, after the payment of all preferential amounts required to be paid to the holders of shares of redeemable convertible preferred stock, the remaining assets of the Company available for distribution to its stockholders were to be distributed among the holders of the shares of redeemable convertible preferred stock and common stock, in proportion to the number of shares held by each such holder, treating for this purpose all such securities as if they had been converted into common stock pursuant to the terms of the Company’s certificate of incorporation immediately prior to such dissolution, liquidation or winding up of the Company.

Redemption Rights

The Company’s certificate of incorporation provided that, unless prohibited by Delaware law governing distributions to stockholders, shares of the redeemable convertible preferred stock were to be redeemed by the Company in three annual installments commencing not more than 60 days after receipt by the Company, at any time on or after July 14, 2020, of written notice from the holders of at least a majority of the outstanding shares of redeemable convertible preferred stock, voting together as a single class on an as-converted basis, requesting redemption of all shares of redeemable convertible preferred stock (a “Redemption Request”).

In that event, unless prohibited by Delaware law governing distributions to stockholders, generally in connection with an insolvent corporation, shares of Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock, respectively, were to be redeemed by the Company at a price equal to the greater of (A) the applicable original issue price per share for such series of redeemable convertible preferred stock, plus any Accruing Dividends accrued but unpaid thereon, whether or not declared, together with any other dividends declared but unpaid thereon, and (B) the fair market value per share of Series A Preferred Stock, Series B Preferred Stock or Series C Preferred Stock, as the case may be, as of the date of the Company’s receipt of the Redemption Request. For purposes of these redemption rights, the fair market value per share of the Series A Preferred Stock was defined as the value per share of Series A Preferred Stock as mutually agreed upon by the Company and the holders of 60% of the shares of Series A Preferred Stock then outstanding, and, in the event that they were unable to reach agreement, by a third-party appraiser agreed to by the Company and the holders of a majority of the shares of Series A Preferred Stock then outstanding; the fair market value per share of the Series B Preferred Stock was defined as the value per share of Series B Preferred Stock as mutually agreed upon by the Company and the holders of 60% of the shares of Series B Preferred Stock then outstanding, and, in the event that they were unable to reach agreement, by a third-party appraiser agreed to by the Company and the holders of a majority of the shares of Series B Preferred Stock then outstanding; and the fair market value per share of the Series C Preferred Stock was defined as the value per share of Series C Preferred Stock as mutually agreed upon by the Company and the holders of 66 2/3% of the shares of Series C Preferred Stock then outstanding, and, in the event that they were unable to reach agreement, by a third-party appraiser agreed to by the Company and the holders of a majority of the shares of Series C Preferred Stock then outstanding.

As a result of the redemption rights described above, the carrying values of Series A Preferred Stock of $21.0 million, Series B Preferred Stock of $33.7 million, and Series C Preferred Stock of $61.0 million as of December 31, 2018, were classified as temporary equity, and were presented between liabilities and stockholders’ equity (deficit) on the Company’s Consolidated Balance Sheets in accordance with ASC 480. The Company was accreting the carrying value of the redeemable convertible preferred stock up to the expected redemption value over the estimated Redemption Period. The accretion included cumulative unpaid and undeclared Accruing Dividends as well as additional increases, if any, when the fair value of the redeemable convertible preferred stock exceeded the liquidation value at any point during the Redemption Period. Upon the IPO, all redeemable convertible preferred shares and Accruing Dividends thereon converted to common shares and all previously unaccreted amounts were fully accreted to the expected redemption value.

At December 31, 2018, the fair values of the Company’s Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock were determined utilizing a probability-weighted modeling approach that included both IPO and non-IPO based scenarios. The non-IPO based scenarios included the fair value estimates of the Company’s common stock, before marketability discount, of $0.47, and each issue of its redeemable convertible preferred stock of: $0.82 for its Series A Preferred Stock; $0.86 for its Series B Preferred Stock; and $1.44 for its Series C Preferred Stock, each calculated at December 31, 2017, as there were no clinical development milestones either achieved or not achieved during the period, and it was deemed that the Company’s total equity value had not changed to any significant degree through the December 31, 2018 measurement date. Additional significant inputs utilized for the non-IPO based scenario was a probability factor of 60% and a marketability discount of 20% applied in arriving at the fair value of the common stock. The IPO-based scenario utilized an expected pre-money valuation upon IPO; cost of equity estimate of 15%; estimated time to IPO date of 0.38 years; and a probability factor of 40%.

At December 31, 2017, the fair value of the Company’s Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock was determined utilizing the OPM; whereby each class of stock is modeled as a call option with a unique claim on the assets of the Company. Stock characteristics that were incorporated directly into the option valuation model include liquidation preferences, participation features, convertibility features and ratios, and value-sharing between classes of stock. The Company’s equity value was estimated by employing a back-solving approach to determine its implied equity value at December 31, 2017 based on the initial closing of the Series C Preferred Stock financing completed in July 2017. A Black-Scholes options pricing approach was utilized under the OPM to determine the fair value of each security, with significant inputs including a $1.44 fair value of the Series C Preferred Stock, a risk-free rate of 1.95%, volatility of 78.0% and a probability-weighted estimate of time to liquidity event of 2.71 years.

Financing costs of approximately $166 that were netted against the proceeds from the 2013 and 2012 Series A Preferred Stock financings were being accreted to Series A Preferred Stock over the period from their respective issuance dates to the earliest redemption date of July 14, 2020. The Company recorded $7 in accretion for financing costs for the year ended December 31, 2019 which includes $5 of previously unaccreted financing costs at the time of the conversion of the Series A Preferred Stock into shares of the Company’s common stock. There was no such accretion for the year ended December 31, 2020. In addition, the investor rights/obligation that was allocated from proceeds from the Series A Preferred Stock financings of $2.8 million, less $520 representing its fair value on the date of its exercise as noted above, was being accreted over the Redemption Period. The Company recorded $84 in accretion of investor rights/obligation in the year ended December 31, 2019 which includes $61 of previously unaccreted investor rights/obligations at the time of the conversion of the Series A Preferred Stock into shares of the Company’s common stock. There was no such accretion for the year ended December 31, 2020.

Financing costs of approximately $76 that were netted against the proceeds from the 2014 Series B Preferred Stock financings were being accreted to Series B Preferred Stock over the period from their respective issuance dates to the earliest redemption date of July 14, 2020. The Company recorded $4 in accretion for financing costs in the year ended December 31, 2019 which includes $3 of previously unaccreted financing costs at the time of conversion of the Series B Preferred Stock into shares of the Company’s common stock. There was no such accretion for the year ended December 31, 2020. In addition, the investor rights/obligation that was allocated from proceeds from the Series B Preferred Stock financings of $2.0 million was being accreted over the remaining Redemption Period discussed above. The Company recorded $117 in accretion of Series B Preferred Stock investor rights/obligation in the year ended December 31, 2019 which includes $85 of previously unaccreted investor rights/obligations at the time of the conversion of the Series B Preferred Stock into shares of the Company’s common stock. There was no such accretion for the year ended December 31, 2020.

Financing costs of approximately $379 that were netted against the proceeds from the 2017, 2018 and 2019 Series C Preferred Stock financings were being accreted to Series C Preferred Stock over the period from their respective issuance dates to the earliest redemption date of July 14, 2020. The Company recorded $223 in accretion for financing costs in the year ended December 31, 2019 which includes $164 of previously unaccreted financing costs at the time of conversion of the Series C Preferred Stock into shares of the Company’s common stock. There was no such accretion for the year ended December 31, 2020.

Optional Conversion

Each holder of Series A, Series B or Series C Preferred Stock was able to convert any or all of such holder’s redeemable convertible preferred stock into common stock at any time. Each share of Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock was convertible into such number of shares of common stock as determined by dividing the original issue price of such series by the conversion price for such series in effect at the time of conversion. As of December 31, 2018, each share of Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock was convertible into common stock at a one-to-one conversion ratio. As of December 31, 2020 and 2019, there were no redeemable convertible preferred shares outstanding as a result of the conversion into common shares in connection with the IPO.

In addition, upon conversion of shares of Series A, Series B or Series C Preferred Stock, a holder was entitled to receive, at the election of the holder, either (i) payment in cash of any Accruing Dividends declared but unpaid thereon, or (ii) such number of shares of common stock as determined by dividing the Accruing Dividends for such share of Series A, Series B or Series C Preferred Stock, by the applicable conversion price for such series of redeemable preferred stock in effect at the time of conversion. The conversion prices for Series A, Series B or Series C Preferred Stock were subject to adjustment based on certain events specified in the Company’s certificate of incorporation, including anti-dilution adjustments.

Mandatory Conversion

Upon the closing of a qualified public offering of common stock, as defined in the Company’s certificate of incorporation, or approval of (i) the holders of at least 60% of the Series A Preferred Stock then outstanding, voting separately as a class, (ii) the holders of at least 60% of the Series B Preferred Stock then outstanding, voting separately as a class and (iii) the holders of at least 66 2/3% of the Series C Preferred Stock then outstanding, voting separately as a class, all outstanding shares of redeemable convertible preferred stock would have automatically converted into common stock at the then-applicable conversion rate for such shares. At December 31, 2020 and 2019, there were no redeemable convertible preferred shares outstanding as a result of the conversion into common shares at a one-for-9.5 conversion ratio, in connection with the IPO.

Voting Rights

Prior to the IPO, and except as otherwise provided by law or by the other provisions of the Company’s certificate of incorporation, the holders of redeemable convertible preferred stock were entitled to vote as one class with the holders of common stock on any matter presented to the stockholders of the Company for their action or consideration at any meeting of stockholders of the Company (or by written consent of stockholders in lieu of a meeting), and each holder of outstanding shares of redeemable convertible preferred stock was entitled to cast the number of votes equal to the number of whole shares of common stock into which the shares of redeemable convertible preferred stock held by such holder were convertible as of the record date for determining stockholders entitled to vote on the matter. The holders of record of the shares of the Company’s Series B Preferred Stock, exclusively and as a separate class, were entitled to elect two directors of the Company, the holders of record of the shares of Series C Preferred Stock, exclusively, and as a separate class, were entitled to elect three directors of the Company, and the holders of record of the shares of common stock of the Company, exclusively and as a separate class, were entitled to elect two directors of the Company.

Registration Rights

The holders of shares of the Company’s common stock issued upon conversion of shares of Series A Preferred Stock, Series B Preferred Stock and Series C Preferred Stock have certain registration rights as set forth in an investors’ rights agreement between the Company and certain of its stockholders.

Stockholders' Equity - Stock Options, Activity (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Number of Option Shares
Outstanding, Beginning	1,675,226
Granted	764,583
Forfeited	(163,463)
Expired	(86,526)
Exercised	(18,343)
Outstanding, Ending	2,171,477	1,675,226
Options exercisable	1,009,847
Options unvested	1,161,630
Weighted Average Exercise Price
Outstanding, Beginning	$ 6.20
Granted	5.11
Forfeited	7.77
Expired	9.18
Exercised	1.82
Outstanding, Ending	5.62	$ 6.20
Options exercisable	4.67
Options unvested	$ 6.44
Weighted Average Contractual Term, Outstanding	7 years 6 months	7 years 9 months 18 days
Weighted Average Contractual Term, Options exercisable	6 years
Weighted Average Contractual Term, Options unvested	8 years 9 months 18 days
Aggregate Intrinsic Value, Outstanding	$ 185	$ 864
Aggregate Intrinsic Value, Options exercisable	$ 185

Leases - Future Minimum Lease Payments (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
2021	$ 138
2022	131
2023	24
Total lease payments	293
Less: imputed discount	(36)
Carrying value of operating lease liabilities	$ 257	$ 356

Consolidated Statements of Redeemable Convertible Preferred Stock and Stockholders' Equity - USD ($) $ in Thousands	Total	Initial Public Offering [Member]	Private Placement [Member]	ATM Sales Agreement [Member]	Common Stock [Member]	Common Stock [Member] Initial Public Offering [Member]	Common Stock [Member] Private Placement [Member]	Common Stock [Member] ATM Sales Agreement [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member] Initial Public Offering [Member]	Additional Paid-in Capital [Member] Private Placement [Member]	Additional Paid-in Capital [Member] ATM Sales Agreement [Member]	Accumulated Deficit [Member]	Series A Redeemable convertible Preferred Stock [Member]	Series B Redeemable convertible Preferred Stock [Member]	Series C Redeemable convertible Preferred Stock [Member]
Beginning Balance at Dec. 31, 2018	$ (109,494)				$ 4								$ (109,498)	$ 21,033	$ 33,686	$ 61,023
Beginning Balance (in shares) at Dec. 31, 2018					438,600									15,387,923	22,608,695	38,097,672
Stock-based compensation	1,127								$ 1,127
Issuance of common stock from exercise of stock options	38								38
Issuance of common stock from exercise of stock options (in shares)					14,736
Issuance of Series C redeemable convertible preferred stock, net of issuance costs																$ 11,059
Issuance of Series C redeemable convertible preferred stock, net of issuance costs (in shares)																6,849,315
Dividends accrued on redeemable convertible preferred stock	(2,239)												(2,239)	$ 326	$ 551	$ 1,362
Dividends accrued on redeemable convertible preferred stock, (in shares)														5,406,844	6,478,999	3,792,386
Accretion (amortization) of premium (discount) on issuance of redeemable convertible preferred stock	(24)												(24)	$ (7)	$ 31
Accretion of discount on investor rights/obligation	(201)												(201)	84	117
Adjustment for excess (shortfall) of fair value over liquidation value of redeemable convertible preferred stock	1,994												1,994	(651)	(940)	$ (403)
Accretion of issuance costs on redeemable convertible preferred stock	(234)												(234)	7	4	223
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering	127,504				$ 7				105,464				22,033	$ (20,792)	$ (33,449)	$ (73,264)
Conversion of redeemable convertible preferred stock to common stock in connection with initial public offering, (in shares)					10,381,234									(20,794,767)	(29,087,694)	(48,739,373)
Issuance of common stock value, net of underwriting discounts and commissions and issuance costs		$ 48,174	$ 13,950			$ 5	$ 2			$ 48,169	$ 13,948
Issuance of common stock shares, net of underwriting discounts and commissions and issuance costs (in shares)						5,500,000	1,500,000
Net loss	(26,050)												(26,050)
Ending Balance at Dec. 31, 2019	54,545				$ 18				168,746				(114,219)
Ending Balance (in shares) at Dec. 31, 2019					17,834,570
Stock-based compensation	2,417								2,417
Issuance of common stock from exercise of stock options	$ 34								34
Issuance of common stock from exercise of stock options (in shares)	18,343				18,343
Issuance of common stock from employee stock purchase plan	$ 12								12
Issuance of common stock from employee stock purchase plan (in shares)					5,997
Issuance of common stock value, net of underwriting discounts and commissions and issuance costs				$ 3,032				$ 1				$ 3,031
Issuance of common stock shares, net of underwriting discounts and commissions and issuance costs (in shares)								687,876
Net loss	(32,758)												(32,758)
Ending Balance at Dec. 31, 2020	$ 27,282				$ 19				$ 174,240				$ (146,977)
Ending Balance (in shares) at Dec. 31, 2020					18,546,786

Income Taxes - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Current state and local tax benefits	$ 18,000	$ 18,000
Current research tax credit receivable	18,000	18,000
Deferred tax assets, valuation allowance	42,829,000	33,295,000
Increase (decrease) in deferred tax assets valuation allowance	9,500,000	7,400,000
Unrecognized tax benefits or related interest and penalties accrued	0	0
Federal and State [Member]
Income Taxes [Line Items]
Net operating loss carryforwards	30,800,000	23,900,000
Operating loss carryforwards	$ 137,600,000	106,800,000
Net operating loss Carryforwards, limitations on use	Due to the Series A preferred stock financing in December 2012 and the shares issued in connection with the Company’s IPO in May 2019, the Company was subject to an “ownership change” under the Code Section 382. As a result, the Company’s ability to utilize approximately $91.3 million of its NOL carryforwards and approximately $3.0 million of research tax credits is limited.
Limitations on use operating loss carryforwards	$ 91,300,000
Percentage of taxable income offset by operating loss carryforwards	80.00%
Federal and State [Member] \| Earliest Tax Year [Member]
Income Taxes [Line Items]
Operating loss carryforwards expiration year	2031
Income tax examination year under examination	2011
Federal and State [Member] \| Latest Tax Year [Member]
Income Taxes [Line Items]
Operating loss carryforwards expiration year	2037
Income tax examination year under examination	2020
Federal [Member]
Income Taxes [Line Items]
R&D tax credits	$ 671,000
R&D tax credits balance	3,900,000	3,200,000
Limitations on use tax credits research	$ 3,000,000
Federal [Member] \| Earliest Tax Year [Member]
Income Taxes [Line Items]
Tax credit carryforwards expiration year	2032
Federal [Member] \| Latest Tax Year [Member]
Income Taxes [Line Items]
Tax credit carryforwards expiration year	2039
State [Member]
Income Taxes [Line Items]
R&D tax credits	$ 133,000	$ 82,000

Debt (Tables)

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Schedule of Outstanding Borrowings under SVB Term Loan

There were no outstanding borrowings under the SVB Term Loan as of December 31, 2019.

	December 31,
	2020
Principal outstanding under term loan	$	14,000
Term loan discount - interest		(158	)
Term loan discount - unamortized deferred charges		(48	)
Term loan discount - financing costs, net of accretion		(23	)
Term loan-final payment fee		183
		13,954
Less current portion		—
Term loan payable, non current	$	13,954

Schedule of Components of Interest Expense of Term Loan

Interest expense on the SVB Term Loan, which is comprised of interest payments, accretion and amortization of term loan discounts and the accrual of the final payment fee, is shown below for the year ended December 31, 2020. There was no such expense under the SVB Term Loan for the year ended December 31, 2019.

	Year Ended December 31,
	2020
Interest payments	$	231
Accretion and amortization of term loan discounts		42
Accrual of the final payment fee		183
	$	456

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

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Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
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+ Details

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Components of Income Tax (Benefit)

The components of income tax (benefit) for the years ended December 31, 2020 and 2019, are as follows:

	Year Ended December 31,
	2020			2019
Current:
Federal	$	—		$	—
State		(18	)		(18	)
		(18	)		(18	)
Deferred:
Federal		—			—
State		—			—
		—			—
Income tax (benefit)	$	(18	)	$	(18	)

Reconciliation Between Income Tax Benefit and Expected Tax Benefit at Statutory Rate

A reconciliation between income tax benefit and the expected tax benefit at the statutory rate for the years ended December 31, 2020 and 2019 is as follows:

	Year Ended December 31,
	2020			2019
Federal statutory income tax rate		21.0	%		21.0	%
State income tax (benefit)—net of federal tax		6.1			5.9
Change in valuation allowance		(29.1	)		(28.2	)
Refundable tax credit		0.1			0.1
R&D tax credits		2.0			1.4
Lease Standard Adoption		—			(0.1	)
Effective income tax rate		0.1	%		0.1	%

Significant Components of Deferred Tax Assets

Significant components of the Company’s deferred tax assets are as follows:

	Year Ended December 31,
	2020			2019
Net operating loss carryforwards	$	37,048		$	28,745
Federal and state tax credits		4,054			3,350
Other		1,727			1,200
		42,829			33,295
Valuation allowance		(42,829	)		(33,295	)
Net deferred tax asset	$	—		$	—

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 45,001	$ 57,313
Tax credit and other receivables	265	558
Prepaid expenses	1,003	1,681
Total current assets	46,269	59,552
Deferred offering costs	284
Operating lease right-of-use asset	227	312
Security deposits and other non-current assets	248	19
Property, equipment and leasehold improvements, net	103	118
Total assets	47,131	60,001
Current liabilities:
Accounts payable	2,016	1,599
Accrued expenses	3,426	3,501
Operating lease liability - current portion	113	99
Total current liabilities	5,555	5,199
Term loan	13,954
Term loan derivative liability	196
Operating lease liability - long term portion	144	257
Commitments and contingencies (Note 12)
Stockholders’ equity:
Common stock: $0.001 par value; 200,000,000 shares authorized at December 31, 2020 and 2019; 18,546,786 and 17,834,570 shares issued and outstanding at December 31, 2020 and 2019, respectively.	19	18
Preferred stock: $0.001 par value; 5,000,000 shares authorized at December 31, 2020 and 2019; no shares issued or outstanding at December 31, 2020 or 2019.
Additional paid-in capital	174,240	168,746
Accumulated deficit	(146,977)	(114,219)
Total stockholders’ equity	27,282	54,545
Total liabilities and stockholders’ equity	$ 47,131	$ 60,001

Income Taxes

12 Months Ended

Dec. 31, 2020

Income Tax Disclosure [Abstract]

Income Taxes

9.	Income Taxes

During each of the years ended December 31, 2020 and 2019, the Company recorded an income tax benefit related to state research and development tax credits of $18, respectively.

The components of income tax (benefit) for the years ended December 31, 2020 and 2019, are as follows:

	Year Ended December 31,
	2020			2019
Current:
Federal	$	—		$	—
State		(18	)		(18	)
		(18	)		(18	)
Deferred:
Federal		—			—
State		—			—
		—			—
Income tax (benefit)	$	(18	)	$	(18	)

A reconciliation between income tax benefit and the expected tax benefit at the statutory rate for the years ended December 31, 2020 and 2019 is as follows:

	Year Ended December 31,
	2020			2019
Federal statutory income tax rate		21.0	%		21.0	%
State income tax (benefit)—net of federal tax		6.1			5.9
Change in valuation allowance		(29.1	)		(28.2	)
Refundable tax credit		0.1			0.1
R&D tax credits		2.0			1.4
Lease Standard Adoption		—			(0.1	)
Effective income tax rate		0.1	%		0.1	%

Significant components of the Company’s deferred tax assets are as follows:

	Year Ended December 31,
	2020			2019
Net operating loss carryforwards	$	37,048		$	28,745
Federal and state tax credits		4,054			3,350
Other		1,727			1,200
		42,829			33,295
Valuation allowance		(42,829	)		(33,295	)
Net deferred tax asset	$	—		$	—

For the years ended December 31, 2020 and 2019, the Company generated federal and state net operating losses (“NOLs”) of approximately $30.8 million and $23.9 million, respectively. At December 31, 2020 and 2019, the Federal and state net operating loss balances were approximately $137.6 million and $106.8 million, respectively. The operating losses generated prior to 2018 will expire in years 2031 through 2037, unless previously utilized. The operating losses generated in 2018 or later can be carried forward indefinitely, however will only offset 80% of taxable income in a carryforward year. The Company also generated federal R&D tax credits in 2020 of approximately $671. At December 31, 2020 and 2019, the federal R&D tax credits were approximately $3.9 million and $3.2 million, respectively. These credits will expire in years 2032 through 2039, unless previously utilized. Due to the Series A preferred stock financing in December 2012 and the shares issued in connection with the Company’s IPO in May 2019, the Company was subject to an “ownership change” under the Code Section 382. As a result, the Company’s ability to utilize approximately $91.3 million of its NOL carryforwards and approximately $3.0 million of research tax credits is limited.

The Company also generated state research tax credits for the years ended December 31, 2020 and 2019 of approximately $133 and $82, respectively. The Company applied to exchange most of these credits for cash under a state-run program. These amounts, $18 and $18 for the years ended December 31, 2020 and 2019, respectively, were recognized as current income tax benefits in the Company’s Consolidated Statements of Operations. At each of December 31, 2020 and 2019, the Company’s Consolidated Balance Sheets reflect income tax receivable of $18 respectively, related to these credits. Because of the net operating loss and research credit carryforwards, tax years 2011 through 2020 remain open to U.S. federal and state tax examinations.

Income taxes are provided using the asset/liability method, in which deferred taxes are recognized for the tax consequences of temporary differences between the financial statement carrying amounts and tax bases of existing assets and liabilities. The Company reviews deferred tax assets for recoverability on a regular basis. In assessing the need for a valuation allowance, the Company considers both positive and negative evidence related to the likelihood of realization of the deferred tax assets. The weight given to the positive and negative evidence is commensurate with the extent to which the evidence may be objectively verified. Accounting guidance states that a cumulative loss in recent years is a significant piece of negative evidence that is difficult to overcome in determining that a valuation allowance is not needed against deferred tax assets. As such, it is generally difficult for positive evidence regarding projected future taxable income exclusive of reversing taxable temporary differences to outweigh objective negative evidence of recent financial reporting losses.

The Company determined that operating losses it incurred since its inception on March 17, 2011, represented negative evidence sufficient to conclude a valuation allowance was necessary. As such, the Company has recorded a valuation allowance of $42.8 million and $33.3 million at December 31, 2020 and 2019, respectively, as a reserve against its net deferred tax assets. These balances reflect increases in the valuation allowance of $9.5 million and $7.4 million in 2020 and 2019, respectively, both representing an increase in net deferred tax assets.

The Company applies the provisions of ASC 740, which prescribes a comprehensive model for how a company should recognize, measure, present, and disclose in its financial statements uncertain tax positions that the Company has taken or expects to take on a tax return. The financial statements reflect expected future tax consequences of such positions presuming the taxing authorities possess full knowledge of the position and all relevant facts. As a result of the implementation of ASC 740, the Company recognized no adjustment for unrecognized income tax benefits. The Company has not, as of yet, conducted a study of R&D tax credit carryforwards. Such a study could result in an adjustment to the Company’s R&D tax credit carryforwards; however, until a study is completed and any potential adjustment is known, no amounts are being presented as an uncertain tax position. A full valuation allowance has been provided against the Company’s R&D tax credits and, if an adjustment is required in the future, this adjustment would be offset by a corresponding adjustment to the valuation allowance. For the years ended December 31, 2020 and 2019, the Company had no unrecognized tax benefits or related interest and penalties accrued. In the event the Company determines that accrual of interest or penalties are necessary in the future, the amount will be presented as a component of interest expense.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References + Details

Collaborative and Licensing Agreements

12 Months Ended

Dec. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Collaborative and Licensing Agreements

11.	Collaborative and Licensing Agreements

The Company enters into collaborative and licensing agreements with pharmaceutical companies to in-license, develop, manufacture and/or market products that fit within its business strategy.

Endo Pharmaceuticals Inc.

In May 2011, the Company entered into an agreement with Penwest Pharmaceuticals Co. (“Penwest”) (subsequently merged into its parent, Endo Pharmaceuticals Inc. (“Endo”)) for an exclusive worldwide sublicensable license under certain patent rights and know-how controlled by Penwest to develop and commercialize products incorporating nalbuphine hydrochloride in any formulation, including an extended release formulation such as Haduvio, in all fields and for any use.

Under the license agreement, the Company paid Penwest a non-creditable, non-refundable upfront license fee of $25. The Company may also become obligated to make milestone payments to Endo of $250, which would become due upon the successful completion of the first Phase 3 clinical trial of a licensed product candidate, such as the Phase 2b/3 PRISM trial, and $750, which would become due upon the marketing approval of a licensed product in the United States, and to pay mid-single-digit royalties based on net sales of the licensed products by the Company, its affiliates and sublicensees. In addition, the Company is obligated to pay Endo a low-to-mid double-digit percentage of certain income it receives from sublicensees, based on the date of the definitive agreement under which the sublicense was granted.

The Company’s royalty obligation with respect to each licensed product in each country commences upon the first commercial sale of the product in that country and extends until the later of the expiration, unenforceability or invalidation of the last valid claim of any licensed patent or application covering the licensed product in the country or the expiration of 10 years after the first commercial sale of the licensed product in the country, which period is referred to as the royalty term. Upon the expiration of the royalty term for a product in a country, the Company is thereafter obligated to pay a low single-digit know-how and trademark royalty.

Under the agreement, the Company has granted Endo a non-exclusive, royalty-free (except for pass-through payments to third parties), sublicensable license under its relevant patent rights, to use any improvement the Company makes to Endo’s controlled release technology, for any product other than the products under which it is licensed by Endo.

Both the Company and Endo have the right to terminate the agreement if the other party materially breaches the agreement and fails to cure the breach within specified cure periods. Endo also has the right to terminate in the event the Company undergoes specified bankruptcy, insolvency or liquidation events, and the Company has the right to terminate the agreement at its convenience at any time on 180 days’ notice to Endo. Additionally, if the Company or any of the Company’s sublicensees challenge the validity or enforceability of any licensed patent rights covering a licensed product, and that challenge is not terminated within a specified period, the agreement will immediately terminate and all licenses granted under the agreement shall be revoked.

Upon termination of the agreement, the Company must transfer to Endo all regulatory filings and approvals relating to the development, manufacture or commercialization of the licensed products and all trademarks, other than the Company’s corporate trademarks, then being used in connection with the licensed products. If the agreement is terminated under certain specified circumstances, the Company will be deemed to have granted Endo a perpetual, royalty-free (except for pass-through payments to third parties), worldwide, exclusive, sublicensable license, under any improvements the Company made to the licensed know-how, and any related patent rights the Company has, to manufacture and commercialize the licensed products.

Exclusive License Agreement with Rutgers

In November 2018, the Company entered into an agreement with Rutgers, The State University of New Jersey (“Rutgers”) for an exclusive, worldwide, sublicensable license under certain patent rights controlled by Rutgers and for a non-exclusive, worldwide, sublicensable license under certain know-how controlled by Rutgers, in each case to develop and commercialize products incorporating nalbuphine for any human or animal use.

Upon entering into the license agreement, the Company paid Rutgers a minimal upfront license issue fee, which was recorded as R&D expense in 2018 and agreed to pay Rutgers a minimal annual license fee. The Company may become obligated to make milestone payments to Rutgers in the aggregate of up to $331 based on the achievement of certain clinical, regulatory and sales milestones. The Company has also agreed to pay Rutgers a low single-digit percentage of certain income it receives from sublicensees and to pay tiered low single-digit royalties based on net sales of licensed products by the Company and its affiliates and sublicensees.

The Company’s royalty obligation with respect to each licensed product in each country commences on the date of the first commercial sale of the licensed product in that country following receipt of marketing approval and extends until the later of the date of expiration, unenforceability or invalidation of the last valid claim of any licensed patent or patent application covering the licensed product in the country and 10 years after the first commercial sale of the first licensed product sold anywhere in the world, which period is referred to as the royalty term. Upon the expiration of the royalty term for a licensed product in a country, the license granted to the Company under the agreement shall become perpetual, fully paid-up, irrevocable and royalty-free in such country. The royalty is subject to reduction in certain circumstances.

Restructuring Agreement with MentiNova, LLC

In November 2018, concurrent with the signing of the agreement with Rutgers described above, the Company entered into a restructuring agreement with MentiNova, LLC (“MentiNova”) for the purchase of specified information and know-how, specified contractual rights and benefits, and all books and records of MentiNova related thereto (collectively, the “Acquired Assets”).

Upon entering into the license agreement, the Company paid MentiNova an aggregate upfront payment of $119, which was recorded as R&D expense in 2018, subject to specified closing adjustments. The Company may become obligated to make milestone payments to MentiNova in the aggregate of up to $1.2 million based on the achievement of certain clinical and regulatory milestones as well as tiered low single-digit royalties based on net sales of products containing nalbuphine as the sole active pharmaceutical ingredient that are developed by the Company using the Acquired Assets or the intellectual property licensed to the Company under the Rutgers agreement described above (the “Rutgers IP”) for indications that are within the scope of the Rutgers IP. The royalty is subject to reduction in certain circumstances.

Subsequent Event - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 24, 2021	Dec. 31, 2020	Dec. 31, 2019
Subsequent Event [Line Items]
Estimated commissions and allocated fees		$ 377	$ 1,213
ATM Sales Agreement [Member]
Subsequent Event [Line Items]
Sale of stock during the period		687,876
Proceeds from issuance of common stock		$ 3,200
Estimated commissions and allocated fees		$ 200
ATM Sales Agreement [Member] \| Subsequent Event [Member]
Subsequent Event [Line Items]
Sale of stock during the period	1,367,621
Proceeds from issuance of common stock	$ 4,400
Estimated commissions and allocated fees	$ 300

Net Loss per Share - Calculation of Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Antidilutive securities excluded from computation of earnings per share, amount	2,171,477	1,675,226
Stock Option [Member]
Antidilutive securities excluded from computation of earnings per share, amount	2,171,477	1,675,226

Income Taxes - Significant Components of Deferred Tax Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Net operating loss carryforwards	$ 37,048	$ 28,745
Federal and state tax credits	4,054	3,350
Other	1,727	1,200
Deferred tax assets, gross	42,829	33,295
Valuation allowance	$ (42,829)	$ (33,295)

Net Loss per Share - Computation of Basic and Diluted Net Loss Per Share Attributable to Common Stockholders (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net loss	$ (32,758)	$ (26,050)
Accretion of redeemable convertible preferred stock		1,535
Dividends accrued on redeemable convertible preferred stock		(2,239)
Adjusted net loss attributable to common stockholders	$ (32,758)	$ (26,754)
Weighted average common shares used in net loss per share attributable to common stockholders, basic and diluted	18,059,011	11,735,781
Basic and diluted net loss per common share outstanding	$ (1.81)	$ (2.28)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

+ Details

- Definition

Amount, after deduction of tax, noncontrolling interests, dividends on preferred stock and participating securities; of income (loss) available to common shareholders.

+ References

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+ Details

Leases

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Leases

Effective March 1, 2013, the Company entered into a lease for office space in New Haven, CT and commencing March 1, 2018, the Company entered into the First Amendment to the lease. The leased space approximates 5,600 square feet and the lease has a term of 60 months. The lease requires monthly payments ranging from approximately $10 to $11 through February 1, 2023 and provides for two designated months of free rent.

Under ASC 842, the Company determines if an arrangement is a lease at its inception. If an operating lease has a term greater than one year, the lease is recognized in the balance sheet as a right-of-use asset and an operating lease liability at lease commencement. The Company elected the short-term lease practical expedient; therefore, if an operating lease has a term less than one year, the Company will not recognize the lease on its balance sheet. The operating right-of-use asset represents the Company’s right of use to an underlying asset for the term of the lease, and the operating liability represents the Company’s obligation to make lease payments arising from the lease.

Operating lease right-of-use assets and operating lease liabilities are determined and recognized on the commencement date of the lease based on the present value of lease payments over the term of the lease. As the Company’s leases do not provide an implicit rate within the lease, the Company uses its incremental borrowing rate, which is updated periodically, based on information available at the commencement date of the lease to determine the present value of the lease payments. The incremental borrowing rate used on existing leases as of December 31, 2020 was 13.0% . The right-of-use asset also includes any lease payments related to initial direct costs and prepayments, and excludes lease incentives. Lease expense is recognized on a straight line basis over the lease term. The Company had no new leases during the years ended December 31, 2020 and 2019.

The Company’s operating leases consist of real estate and equipment and have remaining terms of approximately 2 years and 3 months. The Company has no financing leases. The following table summarizes the Company’s operating leases as presented on its Consolidated Balance Sheets:

	As of December 31,
	2020		2019
Assets:
Operating lease right-of-use asset	$	227	$	312
Liabilities:
Operating lease liabilities, current portion	$	113	$	99
Operating lease liabilities, long term portion		144		257
Total operating lease liabilities	$	257	$	356

Future minimum lease payments under the operating leases are as follows as of December 31, 2020:

	As of December 31, 2020
2021	$	138
2022		131
2023		24
Total lease payments		293
Less: imputed discount		(36	)
Carrying value of operating lease liabilities	$	257

Lease expense under operating leases, including leases of office equipment, was $124 for each of the years ended December 31, 2020 and 2019. Lease payments made were $138 and $125 in the years ended December 31, 2020 and 2019, respectively, with such amounts reflected in the Consolidated Statements of Cash Flows in operating activities.

Net Loss per Share

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Earnings Per Share

10.	Net Loss per Share

The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company:

	As of December 31,
	2020			2019
Net loss	$	(32,758	)	$	(26,050	)
Accretion of redeemable convertible preferred stock		—			1,535
Dividends accrued on redeemable convertible preferred stock		—			(2,239	)
Adjusted net loss attributable to common stockholders	$	(32,758	)	$	(26,754	)
Weighted average common shares used in net loss per share attributable to common stockholders, basic and diluted		18,059,011			11,735,781
Basic and diluted net loss per common share outstanding	$	(1.81	)	$	(2.28	)

Accretion and dividends included in the table above were calculated through the IPO date.

The Company’s potential dilutive securities, which include stock options and, for 2019 through the IPO date, redeemable convertible preferred stock, have been excluded from the computation of diluted net loss per share attributable to common stockholders whenever the effect of including them would be to reduce the net loss per share. In periods where there is a net loss, the weighted average number of common shares outstanding used to calculate both basic and diluted net loss per share attributable to common stockholders is the same. The following potential common shares, presented based on shares outstanding as of December 31, 2020 and 2019, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:

	Shares as of December 31,
	2020		2019
Outstanding stock options		2,171,477		1,675,226
		2,171,477		1,675,226

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (32,758)	$ (26,050)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	47	39
Changes in fair value of obligation for loan success fee		215
Changes in fair value of term loan derivative liability	9
Accretion/accrual of term loan discounts and debt issuance costs	227
Stock-based compensation	2,417	1,127
Changes in operating assets and liabilities:
Receivables	293	(374)
Prepaid expenses	449	(243)
Accounts payable	417	777
Accrued expenses and other	(101)	1,416
Net cash used in operating activities	(29,000)	(23,093)
Investing activities
Acquisitions of property, equipment and leasehold improvements	(32)	(9)
Net cash used in investing activities	(32)	(9)
Financing activities
Payment of loan success fee		(675)
Proceeds from term loan	14,000
Financing costs of term loan	(84)
Proceeds from at-the-market sales, net of commissions	3,135
Proceeds from exercises of stock options	34	38
Proceeds from the employee stock purchase plan	12
Proceeds from sale of Series C redeemable convertible preferred stock, net of issuance costs		9,963
Proceeds from issuance of common shares upon completion of initial public offering, net of underwriting commissions and discounts		51,150
Proceeds from private placement, net of private placement agent fees		13,950
Payments of offering costs	(377)	(1,213)
Net cash provided by financing activities	16,720	73,213
Net cash increase (decrease) for year	(12,312)	50,111
Cash and cash equivalents at beginning of year	57,313	7,202
Cash and cash equivalents at end of year	45,001	57,313
Supplemental disclosure of cash flow information
Interest paid	180
State research tax credits exchanged for cash	18	124
Supplemental disclosure of non-cash financing activities
Offering costs included in accrued expenses	$ 11
Accretion on redeemable convertible preferred stock		(1,535)
Dividends accrued on redeemable convertible preferred stock		$ 2,239

Net Loss per Share (Tables)

12 Months Ended

Dec. 31, 2020

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table summarizes the computation of basic and diluted net loss per share attributable to common stockholders of the Company:

	As of December 31,
	2020			2019
Net loss	$	(32,758	)	$	(26,050	)
Accretion of redeemable convertible preferred stock		—			1,535
Dividends accrued on redeemable convertible preferred stock		—			(2,239	)
Adjusted net loss attributable to common stockholders	$	(32,758	)	$	(26,754	)
Weighted average common shares used in net loss per share attributable to common stockholders, basic and diluted		18,059,011			11,735,781
Basic and diluted net loss per common share outstanding	$	(1.81	)	$	(2.28	)

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

The following potential common shares, presented based on shares outstanding as of December 31, 2020 and 2019, were excluded from the calculation of diluted net loss per share attributable to common stockholders for the periods indicated because including them would have had an anti-dilutive effect:

	Shares as of December 31,
	2020		2019
Outstanding stock options		2,171,477		1,675,226
		2,171,477		1,675,226

Accrued Expenses

12 Months Ended

Dec. 31, 2020

Payables And Accruals [Abstract]

Accrued Expenses

6.	Accrued Expenses

Accrued expenses consist of the following:

	As of December 31,
	2020		2019
Accrued R&D projects	$	1,754	$	2,084
Accrued consulting and professional fees		560		338
Accrued compensation and benefits		954		776
Other		158		303
	$	3,426	$	3,501

Stockholders' Equity - Assumptions on Fair Value of the Stock Options Granted (Detail)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	1.20%	2.00%
Expected volatility	81.50%	78.70%
Expected life of options (in years)	6 years 9 months 18 days	6 years

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2020	Dec. 31, 2019
Statement Of Financial Position [Abstract]
Common Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Common Stock, Shares Authorized	200,000,000	200,000,000
Common Stock, Shares, Issued	18,546,786	17,834,570
Common Stock, Shares, Outstanding	18,546,786	17,834,570
Preferred Stock, Par or Stated Value Per Share	$ 0.001	$ 0.001
Preferred Stock, Shares Authorized	5,000,000	5,000,000
Preferred Stock, Shares Issued	0	0
Preferred Stock, Shares Outstanding	0	0

Debt- Schedule of Components of Interest Expense of Term Loan (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Interest expense	$ 456,000
SVB Term Loan [Member]
Interest payments	231,000
Accretion and amortization of term loan discounts	42,000
Accrual of the final payment fee	183,000
Interest expense	$ 456,000	$ 0

Nature of the Business

12 Months Ended

Dec. 31, 2020

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of the Business

1.	Nature of the Business

Trevi Therapeutics, Inc. (“Trevi” or the “Company”) is a clinical-stage biopharmaceutical company focused on the development and commercialization of Haduvio (nalbuphine ER) to treat serious neurologically mediated conditions. The Company is currently developing Haduvio for the treatment of chronic pruritus associated with prurigo nodularis and chronic cough in patients with idiopathic pulmonary fibrosis (“IPF”). The Company is also in the planning stages for developing Haduvio in levodopa-induced dyskinesia (“LID”) in patients with Parkinson’s disease. These conditions share a common pathophysiology that is mediated through opioid receptors in the central and peripheral nervous systems. Due to nalbuphine’s mechanism of action as a modulator of opioid receptors, the Company believes Haduvio has the potential to be effective in treating each of these conditions.

Haduvio is an oral extended release formulation of nalbuphine. Nalbuphine is a mixed κ-opioid receptor agonist and μ-opioid receptor antagonist that has been approved and marketed as an injectable for pain indications for more than 20 years in the United States and Europe. The κ- and μ-opioid receptors are known to be critical mediators of itch, cough and certain movement disorders. Nalbuphine’s mechanism of action also mitigates the risk of abuse associated with μ-opioid agonists because it antagonizes, or blocks, the μ-opioid receptor. Nalbuphine is currently the only opioid approved for marketing that is not classified as a controlled substance in the United States and most of Europe.

On April 22, 2019, the Company filed an amendment to the Company’s amended and restated certificate of incorporation to effect a one-for-9.5 reverse stock split of the Company’s common stock, which resulted in a proportional adjustment to the existing conversion ratios for each series of the Company’s redeemable convertible preferred stock. Accordingly, all share and per share amounts in the Consolidated Financial Statements have been retrospectively adjusted, where applicable, to reflect the effect of the reverse stock split and adjustments of the redeemable convertible preferred stock conversion for all periods presented.

The accompanying financial statements have been prepared on the basis of continuity of operations, realization of assets and the satisfaction of liabilities and commitments in the ordinary course of business. Since inception, the Company has financed its operations primarily through private placements of its redeemable convertible preferred stock and convertible notes as well as borrowings under term loan facilities, with proceeds from the Company’s initial public offering (“IPO”) and concurrent private placement completed in May 2019 and with sales of common stock under the Company’s sales agreement with SVB Leerink LLC (the “ATM Sales Agreement”). The Company has incurred recurring losses since inception, including net losses attributable to the Company of $32.8 million and $26.1 million for the years ended December 31, 2020 and 2019, respectively. In addition, as of December 31, 2020, the Company had an accumulated deficit of $147.0 million. The Company expects to continue to generate operating losses for the foreseeable future. As of March 25, 2021, the issuance date of these Consolidated Financial Statements, the Company expects that its cash and cash equivalents of $45.0 million as of December 31, 2020, in addition to proceeds from the ATM Sales Agreement subsequent to December 31, 2020, will be sufficient to fund its operating expenses and capital expenditure requirements through at least 12 months from the date of issuance of these Consolidated Financial Statements.

Commitments and Contingencies

12 Months Ended

Dec. 31, 2020

Commitments And Contingencies Disclosure [Abstract]

Commitments and Contingencies

12.	Commitments and Contingencies

A significant portion of the Company’s development activities are outsourced to third parties under agreements, including with clinical research organizations, and contract manufacturers in connection with the production of clinical trial materials. These arrangements may require the Company to pay termination costs to the third parties for reimbursement of costs and expenses incurred in the event of the orderly termination of contractual services.

The Company also has commitments under lease and licensing agreements (Note 4 and Note 11).

Leases (Tables)

12 Months Ended

Dec. 31, 2020

Leases [Abstract]

Schedule of Balance Sheet Information Related to Operating Leases

The following table summarizes the Company’s operating leases as presented on its Consolidated Balance Sheets:

	As of December 31,
	2020		2019
Assets:
Operating lease right-of-use asset	$	227	$	312
Liabilities:
Operating lease liabilities, current portion	$	113	$	99
Operating lease liabilities, long term portion		144		257
Total operating lease liabilities	$	257	$	356

Future Minimum Lease Payments for Non-cancellable Operating Leases

Future minimum lease payments under the operating leases are as follows as of December 31, 2020:

	As of December 31, 2020
2021	$	138
2022		131
2023		24
Total lease payments		293
Less: imputed discount		(36	)
Carrying value of operating lease liabilities	$	257

Debt

12 Months Ended

Dec. 31, 2020

Debt Disclosure [Abstract]

Debt

Silicon Valley Bank Term Loan

On August 13, 2020 (the “Effective Date”), the Company entered into a loan and security agreement (the “SVB Loan Agreement”) with Silicon Valley Bank, as lender (“SVB”), pursuant to which SVB provided a term loan to the Company in the original principal amount of $14.0 million (the “SVB Term Loan”). The Company may use the proceeds from the SVB Term Loan for working capital and general corporate purposes. The SVB Term Loan bears interest at a floating rate per annum equal to the greater of (A) the prime rate plus 1.00% and (B) 4.25%. If SVB receives evidence satisfactory to it that the Company has (i) received positive data for the Phase 2b/3 clinical trial of Haduvio sufficient to advance Haduvio into a second Phase 3 clinical trial for prurigo nodularis, and (ii) raised sufficient financing to fund such Phase 3 clinical trial and the Company’s operations, (together, the “Phase 3 Event”), the interest rate under the SVB Term Loan will be adjusted to a floating rate equal to the greater of (A) the prime rate plus 3.00% and (B) 6.25% (see term loan derivative liability discussion below). On the first business day of each month, the Company will be required to make monthly interest payments and commencing on March 1, 2022, the Company will be required to repay the SVB Term Loan in 24 consecutive installments of principal plus monthly payments of accrued interest. All outstanding principal and accrued and unpaid interest under the SVB Term Loan and all other outstanding obligations with respect to the SVB Term Loan are due and payable in full on February 1, 2024. The SVB Loan Agreement permits voluntary prepayment of all, but not less than all, of the SVB Term Loan, subject to a prepayment premium. Such prepayment premium would be 3.00% of the principal amount of the SVB Term Loan if prepaid prior to the first anniversary of the Effective Date, 2.00% of the principal amount of the SVB Term Loan if prepaid on or after the first anniversary of the Effective Date but prior to the second anniversary of the Effective Date, and 1.00% of the principal amount of the SVB Term Loan if prepaid on or after the second anniversary of the Effective Date but prior to February 1, 2024. Upon repayment in full of the SVB Term Loan, the Company will be required to pay a final payment fee equal to $1.2 million. The SVB Term Loan and related obligations under the SVB Loan Agreement are secured by substantially all of the Company’s properties, rights and assets, except for its intellectual property (which is subject to a negative pledge under the SVB Loan Agreement). If the Company fails to meet certain equity raise requirements under the SVB Loan Agreement, it will be required to deposit unrestricted and unencumbered cash equal to 100% of the principal amount of the SVB Term Loan then outstanding in a cash collateral account with SVB, which can be used by SVB to prepay the SVB Term Loan at any time. The SVB Loan Agreement contains customary representations, warranties, events of default and covenants. The occurrence and continuation of an event of default could cause interest to be charged at the rate that is otherwise applicable plus 5.00% (unless SVB elects to impose a smaller increase) and would provide SVB with the right to accelerate all obligations under the SVB Loan Agreement, and exercise remedies against the Company and the collateral securing the SVB Term Loan and other obligations under the SVB Loan Agreement, including foreclosure against assets securing the SVB Term Loan and other obligations under the SVB Loan Agreement, including the Company’s cash.

In August 2020, in connection with the SVB Term Loan, the Company paid $57 in financing costs to a third party, which were recorded as deferred charges—loan and will be amortized over the life of the SVB Term Loan using the effective interest method. Amortization of these deferred financing charges totaled $9 for the year ended December 31, 2020, and is included in interest expense in the Company’s Consolidated Statements of Operations. Loan discount—unamortized deferred charges totaled $48 for the year ended December 31, 2020, and is included as a direct reduction of the carrying value of the term loan payable on the Company’s Consolidated Balance Sheet.

In August 2020, in connection with the execution of the SVB Loan Agreement, the Company paid $27 in financing costs to SVB, which were recorded as loan discounts. These loan discounts are included as a reduction in the balance of the term loan payable on the Company’s Consolidated Balance Sheet and will be accreted over the life of the SVB Term Loan using the effective interest method. Accretion of these loan discounts totaled $4 for the year ended December 31, 2020, and is included in interest expense in the Company’s Consolidated Statements of Operations. At December 31, 2020 the loan discount-financing costs balance was $23.

In connection with the SVB Loan Agreement, the Company is obligated to pay a final payment fee of $1.2 million upon repayment in full of the SVB Term Loan. The final payment fee is being accrued over the life of the SVB Term Loan using the effective interest method and is included as an increase in the balance of the term loan payable on the Company’s Consolidated Balance Sheet. For the year ended December 31, 2020, $183 was accrued for the final payment fee, with such amount included in interest expense in the Company’s Consolidated Statements of Operations.

Upon the occurrence of the Phase 3 Event, the interest rate on the SVB Term Loan will increase by 2.00% (the “Contingent Interest Rate Increase”) as described above. The Contingent Interest Rate Increase represents a free-standing financial instrument. Accordingly, the Company accounted for the Contingent Interest Rate Increase as a derivative under ASC 815, Derivatives and Hedging, and therefore, recorded a term loan derivative liability for the Contingent Interest Rate Increase at its fair value of $187 on the Effective Date of the SVB Loan Agreement. The Company adjusts this liability to fair value at each reporting date it remains outstanding, with such adjustments recorded as non-cash charges in other income (expense) in the Company’s Consolidated Statements of Operations. The total fair value of this liability was determined to be $196 at December 31, 2020. The change in fair value of the term loan derivative liability as of December 31, 2020 as compared to the fair value at its last measurement date (its date of inception) was $9. The term loan derivative liability is presented as a non-current liability in the Company’s Consolidated Balance Sheet as of December 31, 2020. Upon recording such term loan derivative liability, the Company also recorded an offsetting term loan discount – interest, to be amortized to interest expense in the Company’s Consolidated Statements of Operations through the SVB Term Loan’s maturity date using the effective interest method. Such amortization was $29 for the year ended December 31, 2020. At December 31, 2020, the balance of the term loan discount – interest was $158 and is included as a reduction in the balance of the term loan payable on the Company’s Consolidated Balance Sheet as of December 31, 2020.

Fair values of the term loan derivative liability are estimated utilizing a probability-weighted cash flow approach, including variables for the timing of the Phase 3 Event and other probability estimates. For the fair value calculations of the term loan derivative liability at its inception and at December 31, 2020, significant inputs included the Contingent Interest Rate Increase of 2.00%, a discount rate of 12.0%; and the SVB Term Loan maturity date of February 1, 2024.

For the year ended December 31, 2020, interest expense under the SVB Term Loan totaled $456, which includes amortization of deferred financing charges, accretion of loan discount-financing costs, accrual of the final payment fee, amortization of the term loan discount-interest and the stated interest on the SVB Term Loan, all as described above. There was no such interest expense on the SVB Term Loan for the year ended December 31, 2019. As of December 31, 2020, the Company had outstanding borrowings of $14.0 million under the SVB Term Loan and the term loan payable balance as presented in the Company’s Consolidated Balance Sheet as of December 31, 2020 was comprised as shown below. There were no outstanding borrowings under the SVB Term Loan as of December 31, 2019.

	December 31,
	2020
Principal outstanding under term loan	$	14,000
Term loan discount - interest		(158	)
Term loan discount - unamortized deferred charges		(48	)
Term loan discount - financing costs, net of accretion		(23	)
Term loan-final payment fee		183
		13,954
Less current portion		—
Term loan payable, non current	$	13,954

	Year Ended December 31,
	2020
Interest payments	$	231
Accretion and amortization of term loan discounts		42
Accrual of the final payment fee		183
	$	456

Solar Capital Term Loan

On December 29, 2014, the Company entered into a loan and security agreement (the “Loan Agreement”) with Solar Capital, Ltd. (“Solar”) and Square 1 Bank (“Square 1”), together (the “Lenders”), which provided $15.0 million in debt financing (the “Term Loan”). On June 29, 2018, the maturity date of the Loan Agreement, the Company made its final payments of principal, interest and all final fees due to the Lenders in connection with the Term Loan. As a result, there were no outstanding borrowings under the Term Loan as of December 31, 2020 and 2019, and the Company’s obligations to the Lenders under the Loan Agreement, other than the obligations under the Success Fee Agreement as described below, were terminated.

Under the terms of the Loan Agreement, the Company was obligated to pay the Lenders a Success Fee (“Success Fee”) under a Success Fee Agreement (“Success Fee Agreement”) upon the first occurrence of an Exit Event, as defined. The Exit Event included, among other things, the completion of a public offering of common stock. The amount of the Success Fee was equal to 4.5% of the $15.0 million Term Loan funded. The Success Fee Agreement was scheduled to terminate on the earlier to occur of (a) payment in full of the Success Fee pursuant to its terms, or (b) December 29, 2021. The completion of the IPO on May 9, 2019 (see Note 8) triggered the Success Fee payment obligation and the Company made payments to its Lenders totaling $675 in May 2019. Upon such payments, the Success Fee Agreement terminated.

The Success Fee Agreement represented a free-standing financial instrument. Accordingly, the Company accounted for the Success Fee provision as a derivative under ASC 815, Derivatives and Hedging, and therefore recorded an obligation for the Success Fee at its fair value on the closing date of each advance under the Loan Agreement. Upon recording such obligations for the Success Fee, the Company also recorded an offsetting loan discount, which was accreted to interest expense in the Company’s Statements of Operations through the Term Loan’s maturity date. The Company adjusted these liabilities for the Success Fee to fair value at each reporting date they remained outstanding. As discussed above, the Success Fee was paid in May 2019; and therefore, the total fair value of the Success Fee liabilities was $0 at December 31, 2020 and 2019. The Company recorded non-cash charges in the amount of $0 and $215 for the years ended December 31, 2020 and 2019, respectively, representing the changes in the fair value of these liabilities since their last measurement date. The fair values of the obligation for the Success Fee were estimated utilizing a probability-weighted cash flow approach, including variables for the timing of the Exit Event and other probability estimates. The non-cash charges are included in other income (expense) in the Company’s Consolidated Statements of Operations.

Income Taxes - Components of Income Tax (Benefit) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Current:
State	$ (18)	$ (18)
Current Federal, State and Local, Tax Expense (Benefit), Total	(18)	(18)
Deferred:
Income tax (benefit)	$ (18)	$ (18)

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Basis of Presentation

Use of Estimates

Cash Equivalents

The Company classifies short-term, highly liquid investments with an original term of three months or less at the date of purchase as cash equivalents.

Fair Value Measurements

Level 1—Observable inputs—quoted prices in active markets for identical assets and liabilities.

Level 3—Unobservable inputs—includes amounts derived from valuation models where one or more significant inputs are unobservable and require the company to develop relevant assumptions.

	Level 1		Level 2		Level 3
December 31, 2020
Financial assets carried at fair value:
Money market funds	$	44,095	$	—	$	—

Financial liabilities carried at fair value:
Term loan derivative liability	$	—	$	—	$	196

December 31, 2019
Financial assets carried at fair value:
Money market funds	$	54,593	$	—	$	—

The following table represents a roll-forward of the fair value of Level 3 instruments (significant unobservable inputs):

	December 31,
	2020		2019
Financial liabilities
Balance at beginning of year⁽¹⁾	$	—	$	1,556
Term loan derivative liability		187		—
Unrealized loss on obligation for loan success fee		—		215
Unrealized loss on obligation for term loan derivative		9		—
Net settlements⁽²⁾		—		(1,771	)
Ending balance	$	196	$	—

(1)	The balance at January 1, 2019 relates to the $460 obligation for the loan success fee and the $1,096 fair value of the Series C redeemable convertible preferred stock liability at the time of the third tranche of the Series C Preferred Stock financing in January 2019.

(2)

Property, Equipment and Leasehold Improvements

Impairment of Long-Lived Assets

Foreign Currency Transactions

Deferred Offering Costs

Research and Development Expenses

Accrued Research and Development Expenses

Patent Costs

Stock-Based Compensation

Risk-Free Interest Rate—The risk-free interest rate is based on the yield available on U.S. Treasury zero-coupon issues similar in duration to the expected term of the equity-settled award.

•

Income Taxes

Redeemable Convertible Preferred Shares

Basic and Diluted Net Income (Loss) per Common Share

Segments

Recently Adopted and Issued Accounting Pronouncements

Recently Adopted Accounting Pronouncements

There have been no new accounting pronouncements adopted during the year ended December 31, 2020.

Recently Issued Accounting Pronouncements

There have been no new accounting pronouncements issued during the year ended December 31, 2020, which could be expected to materially impact the Company’s Consolidated Financial Statements.

Summary of Significant Accounting Policies - Additional Information (Detail)

1 Months Ended

12 Months Ended

May 09, 2019

May 31, 2019

USD ($)

Dec. 31, 2020

USD ($)

Segment

Dec. 31, 2019

USD ($)

Dec. 31, 2018

USD ($)

Summary Of Significant Accounting Policies [Line Items]

Loan success fee payable

$ 675,000

$ 460,000

Impairment of long-lived assets

$ 0

Disposal of long-lived assets

Dividends, common stock, cash

$ 0

Dividend rate, percentage

6.00%

Number of reporting segment | Segment

Number of operating segment | Segment

Redeemable Convertible Preferred Shares [Member]

Summary Of Significant Accounting Policies [Line Items]

Dividend rate, percentage

6.00%

ATM Sales Agreement [Member]

Summary Of Significant Accounting Policies [Line Items]

Deferred offering costs

$ 284,000

Reduction in stockholders' equity

$ 105,000

Computer Equipment [Member]

Summary Of Significant Accounting Policies [Line Items]

Property, Equipment and leasehold improvements, useful life

3 years

Furniture and Office Equipment [Member]

Summary Of Significant Accounting Policies [Line Items]

Property, Equipment and leasehold improvements, useful life

5 years

Series C Convertible Preferred Stock [Member]

Summary Of Significant Accounting Policies [Line Items]

Financial liabilities

$ 1,096,000

Settlements of fair value liability

1,096,000

Fair Value, Measurements, Recurring [Member]

Summary Of Significant Accounting Policies [Line Items]

Financial liabilities

Settlements of fair value liability

^[1]

$ (1,771,000)

[1]

Stockholders' Equity - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended	12 Months Ended
	May 09, 2019	Jun. 30, 2020	Mar. 24, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 26, 2013
Stockholders Equity [Line Items]
Preferred stock, shares authorized				5,000,000	5,000,000
Common stock, shares authorized				200,000,000	200,000,000
Common stock, par or stated value per share				$ 0.001	$ 0.001
Common stock, capital shares reserved for future issuance				3,646,200	2,778,812
Share Price						$ 1.00
Proceeds from public offering					$ 51,150,000
Estimated commissions and allocated fees				$ 377,000	$ 1,213,000
ATM Sales Agreement [Member]
Stockholders Equity [Line Items]
Sale of stock during the period				687,876
Aggregate offering price of common stock which may issue and sell under agreement		$ 12,000,000
Proceeds from issuance of common stock				$ 3,200,000
Estimated commissions and allocated fees				$ 200,000
ATM Sales Agreement [Member] \| Subsequent Event [Member]
Stockholders Equity [Line Items]
Sale of stock during the period			1,367,621
Proceeds from issuance of common stock			$ 4,400,000
Estimated commissions and allocated fees			$ 300,000
Initial Public Offering [Member]
Stockholders Equity [Line Items]
Sale of stock during the period	7,000,000
Share Price	$ 10.00
Proceeds from public offering	$ 62,100,000
Underwriting discounts and commissions	4,900,000
Other offering expenses	$ 3,000,000

Prepaid Expenses - Schedule of Prepaid Expenses (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Prepaid Expense Current [Abstract]
Prepaid R&D payments	$ 333	$ 1,113
Prepaid corporate insurance	562	491
Other	108	77
Prepaid expense	$ 1,003	$ 1,681

Summary of Significant Accounting Policies - Schedule of Fair Value, Financial Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Thousands

12 Months Ended

Dec. 31, 2020

Dec. 31, 2019

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Balance at beginning of year

^[1]

$ 1,556

Net settlements

^[2]

(1,771)

Ending balance

$ 196

Term Loan Derivative Liability [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Term loan derivative liability

187

Unrealized loss on financial liabilities

$ 9

Obligations [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Unrealized loss on financial liabilities

$ 215

[1]	The balance at January 1, 2019 relates to the $460 obligation for the loan success fee and the $1,096 fair value of the Series C redeemable convertible preferred stock liability at the time of the third tranche of the Series C Preferred Stock financing in January 2019.
[2]	The net settlements in the year ended December 31, 2019 relate to the $1,096 fair value of the Series C redeemable convertible preferred stock liability at the time of the third tranche of the Series C Preferred Stock financing in January 2019 and the payment of the $675 obligation for the loan success fee in May 2019.

Stockholders’ Equity (Tables)

12 Months Ended

Dec. 31, 2020

Stockholders Equity Note [Abstract]

Schedule of Common Stock Reserved for Future Issuance

	As of December 31,
	2020		2019
Shares of common stock reserved for future issuance under the 2012 Stock Incentive Plan		921,824		1,043,992
Shares of common stock reserved for future issuance under the 2019 Stock Incentive Plan		2,396,922		1,579,714
Shares of common stock reserved for future issuance under the 2019 Employee Stock Purchase Plan		327,454		155,106
		3,646,200		2,778,812

Schedule of Share-based Compensation, Stock Options, Activity

A summary of the Company’s combined stock option activity for the 2019 Plan and the 2012 Plan for the year ended December 31, 2020 is as follows:

	Number of Option Shares			Weighted Average Exercise Price		Weighted Average Contractual Term		Aggregate Intrinsic Value
						(in years)		(in thousands)
Outstanding as of December 31, 2019		1,675,226		$	6.20		7.8	$	864
Granted		764,583			5.11
Forfeited		(163,463	)		7.77
Expired		(86,526	)		9.18
Exercised		(18,343	)		1.82
Outstanding as of December 31, 2020		2,171,477		$	5.62		7.5	$	185
Options exercisable as of December 31, 2020		1,009,847		$	4.67		6.0	$	185
Options unvested as of December 31, 2020		1,161,630		$	6.44		8.8	$	—

Assumptions on Fair Value of the Stock Options Granted

The assumptions that the Company used to determine the fair value of the stock options granted were as follows, presented on a weighted average basis:

	Year Ended December 31,
	2020			2019
Risk-free interest rate		1.2	%		2.0	%
Expected volatility		81.5	%		78.7	%
Expected dividend yield		—			—
Expected life of options (in years)		6.8			6.8

Schedule of Stock-based Compensation Expenses Recognized

The following table summarizes the classifications of stock-based compensation expenses for the 2012 Plan, the 2019 Plan and the 2019 ESPP recognized in the Consolidated Statements of Operations:

	Year Ended December 31,
	2020		2019
Research and development expense	$	360	$	143
General and administrative expense		2,057		984
	$	2,417	$	1,127

Property, Equipment and Leasehold Improvements, Net

12 Months Ended

Dec. 31, 2020

Property Plant And Equipment [Abstract]

Property, Equipment and Leasehold Improvements, Net

5.	Property, Equipment and Leasehold Improvements, Net

Property, equipment and leasehold improvements, net consist of the following:

	As of December 31,
	2020			2019
Computer, website development and office equipment	$	45		$	45
Furniture and fixtures		60			28
Leasehold improvements		130			130
		235			203
Less accumulated depreciation		(132	)		(85	)
	$	103		$	118

Depreciation was $47 and $39 for the years ended December 31, 2020 and 2019, respectively.

Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on Recurring Basis

	Level 1		Level 2		Level 3
December 31, 2020
Financial assets carried at fair value:
Money market funds	$	44,095	$	—	$	—

Financial liabilities carried at fair value:
Term loan derivative liability	$	—	$	—	$	196

December 31, 2019
Financial assets carried at fair value:
Money market funds	$	54,593	$	—	$	—

Schedule of Fair Value, Financial Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation

The following table represents a roll-forward of the fair value of Level 3 instruments (significant unobservable inputs):

	December 31,
	2020		2019
Financial liabilities
Balance at beginning of year⁽¹⁾	$	—	$	1,556
Term loan derivative liability		187		—
Unrealized loss on obligation for loan success fee		—		215
Unrealized loss on obligation for term loan derivative		9		—
Net settlements⁽²⁾		—		(1,771	)
Ending balance	$	196	$	—

(1)	The balance at January 1, 2019 relates to the $460 obligation for the loan success fee and the $1,096 fair value of the Series C redeemable convertible preferred stock liability at the time of the third tranche of the Series C Preferred Stock financing in January 2019.

(2)

Debt - Schedule of Outstanding Borrowings under SVB Term Loan (Detail) - USD ($)	Dec. 31, 2020	Aug. 13, 2020	Dec. 31, 2019
Term loan payable, non current	$ 13,954,000
SVB Term Loan [Member]
Principal outstanding under term loan	14,000,000	$ 14,000,000
Term loan discount - interest	(158,000)
Term loan discount - unamortized deferred charges	(48,000)
Term loan discount - financing costs, net of accretion	(23,000)
Debt instrument, accrued final payment fee	183,000
Loans Payable, Noncurrent	13,954,000
Term loan payable, non current	$ 13,954,000		$ 0

Collaborative and Licensing Agreements - Additional Information (Detail) - USD ($) $ in Thousands		1 Months Ended	12 Months Ended
	May 23, 2011	Nov. 30, 2018	Dec. 31, 2020
Endo Pharmaceuticals Inc [Member]
Upfront license fee	$ 25
Royalty terms			first commercial sale of the product in that country and extends until the later of the expiration, unenforceability or invalidation of the last valid claim of any licensed patent or application covering the licensed product in the country or the expiration of 10 years after the first commercial sale of the licensed product in the country, which period is referred to as the royalty term. Upon the expiration of the royalty term for a product in a country,
Endo Pharmaceuticals Inc [Member] \| Completion Of Stage One [Member]
Milestone payments to be paid			$ 250
Endo Pharmaceuticals Inc [Member] \| Completion Of Stage Two [Member]
Milestone payments to be paid			750
Rutgers [Member]
Milestone payments to be paid			$ 331
Royalty terms			first commercial sale of the licensed product in that country following receipt of marketing approval and extends until the later of the date of expiration, unenforceability or invalidation of the last valid claim of any licensed patent or patent application covering the licensed product in the country and 10 years after the first commercial sale of the first licensed product sold anywhere in the world, which period is referred to as the royalty term. Upon the expiration of the royalty term for a licensed product in a country, the license granted to the Company under the agreement shall become perpetual, fully paid-up, irrevocable and royalty-free in such country.
MentiNova, LLC [Member]
Upfront license fee		$ 119
MentiNova, LLC [Member] \| Completion Of Stage One [Member]
Milestone payments to be paid			$ 1,200